diff --git a/src/core/schema-pack/base/gbrain-creator.yaml b/src/core/schema-pack/base/gbrain-creator.yaml
new file mode 100644
index 000000000..cce3c94ce
--- /dev/null
+++ b/src/core/schema-pack/base/gbrain-creator.yaml
@@ -0,0 +1,97 @@
+# gbrain-creator — content-creator lens pack
+#
+# v0.41 lens packs wave. Declares the atom + concept lifecycle that the
+# downstream wintermute agent ran via its own crons pre-v0.41:
+#
+#   - `atom` page type (NEW to base v0.40 — first introduced here):
+#     single-source extractive primitive from transcripts/meetings/articles.
+#     The `extract_atoms` cycle phase produces these via a Haiku 3-check
+#     quality gate (truism reject, punchline test, entity-page test).
+#
+#   - `concept` page type (already in gbrain-base seed): the synthesize_concepts
+#     phase aggregates atoms by topic cluster, tiers T1-T4 by composite_score,
+#     and writes voice-gated T1 Canon narratives via Sonnet.
+#
+# Cron consolidation: this pack's phases run inside the standard
+# `gbrain dream` cycle. No separate wintermute-side cron required.
+#
+# Calibration: declares `concept_themes` domain using the `cluster_summary`
+# aggregator (descriptive rollup, not Brier — concepts don't have binary
+# outcomes to score against). When this pack is active OR the gbrain-everything
+# meta-pack is active, calibration_profile produces a concept_themes scorecard
+# with tier counts and dominant topics.
+#
+# Frontmatter validators (atom_type closed 11-value enum, virality_score
+# 0-100, emotional_register, tweetable, sensitivity, lesson, source_quote,
+# draft_angles JSONB) are enforced today INSIDE extract_atoms.ts and read
+# from this manifest at runtime via D11. A richer per-page-type
+# frontmatter_validators contract on PageTypeSchema is a v0.42 follow-up
+# (filed in TODOS.md). For v0.41, the enum lives in code with a comment
+# pointing at the eventual manifest surface.
+
+api_version: gbrain-schema-pack-v1
+name: gbrain-creator
+version: 1.0.0
+description: "Content-creator lens. Atoms (single-source extractive nuggets) and concepts (aggregated themes T1-T4). Drives extract_atoms + synthesize_concepts cycle phases. When active, every gbrain dream tick walks recent transcripts/meetings/articles and produces tweetable atoms + tier-promoted concepts. Retires wintermute's parallel atom-pipeline-coordinator cron."
+gbrain_min_version: 0.41.0
+extends: gbrain-base
+borrow_from: []
+
+# Atom + concept inherit takes_kinds from gbrain-base (fact, take, bet, hunch).
+# Creator-pack-specific kinds (e.g. `extracted`) are deferred — atoms are not
+# claims, they're evidentiary extractions; concepts aggregate atoms not takes.
+# takes_kinds intentionally omitted (inherits from base).
+
+# Pack-specific page types. `concept` already exists in gbrain-base seed; we
+# don't re-declare it here (the registry merges parent + child page_types).
+# `atom` is net-new to base.
+page_types:
+  - name: atom
+    primitive: concept
+    path_prefixes:
+      - atoms/
+    aliases: []
+    # extractable: false — atoms ARE the extraction output, not a source for
+    # further fact extraction. extract_facts skips them. extract_atoms skips
+    # them too (imported_from frontmatter marker handles the greenfield case;
+    # the type itself signals "leaf node, no further derivation").
+    extractable: false
+    # expert_routing: false — atoms don't surface in whoknows/find_experts.
+    # Concepts (parent type from base) carry the routing weight for content
+    # discovery; atoms are content-creator-internal raw material.
+    expert_routing: false
+
+# v0.41 T3: phase participation. The runCycle orchestrator gates pack-
+# flavored phases on this list. Pre-existing 17 core phases ALWAYS run
+# regardless of this declaration — `phases:` is additive, not subtractive.
+phases:
+  - extract_atoms
+  - synthesize_concepts
+
+# v0.41 T3: calibration domain declarations. Each entry binds a per-pack
+# scorecard bucket to one of the 4 v1 aggregator kinds. Domain names are
+# open strings (third-party packs add new domains without a gbrain release);
+# aggregator algorithms are the closed AggregatorKind enum (safe SQL stays
+# in code per T3 codex refinement of D6).
+calibration_domains:
+  - name: concept_themes
+    aggregator: cluster_summary
+    page_types:
+      - concept
+
+# Filing rules — date-bucketed atoms (mirrors wintermute's existing layout
+# at ~/git/brain/atoms/{YYYY-MM-DD}/{slug}.md so greenfield migration lands
+# pages in their canonical locations). Concepts flat-filed per base seed.
+filing_rules:
+  - kind: atom
+    directory: atoms/
+    examples:
+      - atoms/2026-05-24/renders-vs-physical-proof
+      - atoms/2026-05-24/ai-compliance-headwinds
+    description: "Single-source extractive nuggets. Date-bucketed by extraction date (NOT source date — multiple atoms from one meeting all land in the day they were extracted). extract_atoms cycle phase writes here."
+  - kind: concept
+    directory: concepts/
+    examples:
+      - concepts/ai-agents
+      - concepts/founder-psychology
+    description: "Aggregated themes T1-T4 by composite_score (mention_count × distinct_months × breadth). synthesize_concepts writes here. T1 Canon concepts carry Sonnet-synthesized narratives gated by the same voice_gate as calibration_profile."
diff --git a/src/core/schema-pack/base/gbrain-engineer.yaml b/src/core/schema-pack/base/gbrain-engineer.yaml
new file mode 100644
index 000000000..f0f6491fa
--- /dev/null
+++ b/src/core/schema-pack/base/gbrain-engineer.yaml
@@ -0,0 +1,113 @@
+# gbrain-engineer — engineer / code-author lens pack
+#
+# v0.41 lens packs wave. Bridge-only pack (D8-C — locked at plan time
+# after assessing what already exists in gstack):
+#
+#   - gstack already ships review, investigate, plan-eng-review, health,
+#     qa, retro, learn, cso skills with a typed JSONL learnings system
+#     at ~/.gstack/projects/{repo}/learnings.jsonl (pattern, pitfall,
+#     preference, architecture, tool, operational, investigation).
+#   - gbrain already ships `type: code` + code-def/code-refs/code-callers.
+#   - gbrain already ships `type: project` + brain/projects/ directory.
+#
+# What's missing: the gstack learnings JSONL never reaches gbrain. T8
+# fixes that with an IngestionSource bridge that watches the JSONL files
+# and emits IngestionEvent per line typed as `learning` page.
+#
+# Scope deliberately small: declares the `learning` page type (NEW) and
+# reuses `code` from gbrain-base. Drops the speculative ADR / postmortem /
+# refactor_thesis / tech_debt types from the original plan because:
+#   (a) gstack's investigation + retro skills already capture postmortems
+#       and architecture decisions inline (no dedicated type needed)
+#   (b) shipping types nobody authors is worse than no types at all
+#   (c) v0.42+ can add them when first user authors one
+#
+# Calibration: declares 3 engineering domains (architecture_calls,
+# effort_estimates, risk_assessment). All scalar_brier except
+# effort_estimates which uses weighted_brier — small estimates that are
+# wrong cost less than big estimates that are wrong.
+#
+# Does NOT declare new cycle phases. Engineering work consumes the
+# existing extract_facts + propose_takes + grade_takes + calibration_profile
+# loop, augmented by the gstack-learnings IngestionSource (T8) running in
+# the v0.38 daemon when this pack is active.
+
+api_version: gbrain-schema-pack-v1
+name: gbrain-engineer
+version: 1.0.0
+description: "Engineer / code-author lens. Bridges gstack's typed JSONL learnings system (pattern, pitfall, architecture, tool, operational, investigation) into gbrain as first-class `learning` pages. Declares architecture_calls, effort_estimates, risk_assessment calibration domains. Reuses gbrain-base's `code` page type unchanged."
+gbrain_min_version: 0.41.0
+extends: gbrain-base
+
+# Reuse `code` + `project` from base. The gstack-learnings bridge writes
+# `learning` pages cross-referenced to code:// URIs via link_types, but
+# we don't introduce new code-related page types here.
+borrow_from:
+  - pack: gbrain-base
+    types:
+      - code
+      - project
+
+# Engineering uses the same takes_kinds as base (fact, take, bet, hunch).
+# `bet` is the load-bearing one for architecture_calls (a bet on a
+# refactor's payoff is a take).
+# takes_kinds intentionally omitted (inherits from base).
+
+# Pack-specific page types. ONLY `learning` is new (D8-C: bridge-only).
+page_types:
+  - name: learning
+    primitive: annotation
+    path_prefixes:
+      - learnings/
+      - engineering/learnings/
+    aliases: []
+    # extractable: false — learnings ARE distilled engineering insights;
+    # they're not raw source material for further fact extraction.
+    extractable: false
+    # expert_routing: false — learnings surface in code-aware queries
+    # via direct slug search, not via whoknows/find_experts (whoknows is
+    # person+company shaped, learnings are pattern shaped).
+    expert_routing: false
+
+# No new cycle phases. Engineering consumes existing pipeline.
+# gstack-learnings IngestionSource (T8) emits events when this pack is
+# active — handled by the v0.38 daemon's normal trickle-mode dispatch.
+phases: []
+
+# v0.41 T3: engineering-flavored calibration domains.
+calibration_domains:
+  - name: architecture_calls
+    # "How often I'm wrong about which architecture to pick" — scalar
+    # Brier over resolved code-attached + learning-attached binary takes
+    # (e.g. "this refactor was worth it" resolved true/false).
+    aggregator: scalar_brier
+    page_types:
+      - code
+      - learning
+
+  - name: effort_estimates
+    # Weighted Brier — a 1-day-estimate miss costs less than a 1-quarter
+    # estimate miss. Weight by take.confidence so high-conviction
+    # estimates that fail count more.
+    aggregator: weighted_brier
+    page_types:
+      - project
+
+  - name: risk_assessment
+    # "How often I correctly flag a risk" — scalar Brier over project-
+    # attached binary takes (e.g. "this rollout will OOM" resolved
+    # true/false). Distinct from architecture_calls (those are go/no-go
+    # decisions on direction; risk_assessment is about specific failure
+    # mode predictions).
+    aggregator: scalar_brier
+    page_types:
+      - project
+
+# Filing rules.
+filing_rules:
+  - kind: learning
+    directory: learnings/
+    examples:
+      - learnings/2026-05/orbstack-port-8080-conflict
+      - learnings/2026-05/django-form-cleaned-data-defaults-empty
+    description: "Engineering learnings bridged from gstack's ~/.gstack/projects/{repo}/learnings.jsonl. Per-month subdirectories. Frontmatter carries the original JSONL fields verbatim: learning_type (one of: pattern, pitfall, preference, architecture, tool, operational, investigation), confidence (1-10), source (one of: observed, user-stated, inferred, cross-model), files (paths), skill (originating gstack skill name)."
diff --git a/src/core/schema-pack/base/gbrain-everything.yaml b/src/core/schema-pack/base/gbrain-everything.yaml
new file mode 100644
index 000000000..afdbefd7b
--- /dev/null
+++ b/src/core/schema-pack/base/gbrain-everything.yaml
@@ -0,0 +1,121 @@
+# gbrain-everything — meta-pack stacking all three lenses
+#
+# v0.41 lens packs wave. Codex outside-voice T4 resolution: gbrain's
+# 7-tier active-pack resolver is single-valued, but the user's actual
+# workflow needs creator + investor + engineer simultaneously (Garry
+# switches between YC investor work, content creation, and gstack
+# engineering across the same day). Two paths to "three lenses on one
+# brain":
+#
+#   A) New active-multi-pack composition concept. New code, new
+#      architecture, new corners. Deferred per plan's NOT-in-scope.
+#
+#   B) Compose via the v0.38-shipped extends chain. Author a meta-pack
+#      that extends one of the three, and bring the other two via
+#      borrow_from. registry walks the chain, unions page_types +
+#      link_types + phases + calibration_domains. ZERO new architecture.
+#
+# This pack is path B. Activate via `gbrain config set schema_pack
+# gbrain-everything` and the brain runs all three lens-pack phases
+# (extract_atoms + synthesize_concepts from creator; gstack-learnings
+# bridge from engineer) AND surfaces all 7 calibration domains
+# (_overall + concept_themes + deal_success + founder_evaluation +
+# market_call + architecture_calls + effort_estimates + risk_assessment).
+#
+# Extension chain (registry resolves via extends.parent.parent.parent):
+#
+#     gbrain-everything ──extends──▶ gbrain-investor ──extends──▶ gbrain-base
+#                       │ borrow                     │
+#                       ├─ gbrain-creator
+#                       └─ gbrain-engineer
+#
+# Single-active-pack constraint preserved: this IS the active pack.
+# Registry walks its dependencies through extends + borrow_from to
+# materialize the merged view. Tested by the everything-manifest test.
+
+api_version: gbrain-schema-pack-v1
+name: gbrain-everything
+version: 1.0.0
+description: "Meta-pack stacking creator + investor + engineer lenses on one brain. Use this when you do investor work AND content creation AND engineering in the same brain (YC president pattern, founder pattern). Single active-pack activation via `gbrain config set schema_pack gbrain-everything` — registry walks extends + borrow_from chain to union all three lenses' page_types, phases, and calibration_domains."
+gbrain_min_version: 0.41.0
+
+# Extends gbrain-investor (which itself extends gbrain-base) and borrows
+# from gbrain-creator + gbrain-engineer. The registry's extends chain
+# walker (cap depth 8) unions every level's contributions.
+extends: gbrain-investor
+
+# Borrow types + link_types from the other two lens packs. This is the
+# composition mechanism that makes "three lenses" real without a
+# multi-active-pack architecture.
+borrow_from:
+  - pack: gbrain-creator
+    types:
+      - atom
+      # concept already in base
+  - pack: gbrain-engineer
+    types:
+      - learning
+      # code + project already in base
+
+# No new page types declared here — everything comes via extends + borrow.
+page_types: []
+
+# Union of creator + engineer phase declarations. Investor pack declares
+# no phases (consumes existing pipeline), so nothing inherited from the
+# extends chain there. Creator's phases must be re-declared explicitly
+# because `borrow_from` borrows types/link_types only, NOT phases (D4-B
+# decision: each pack declares its phase participation explicitly).
+#
+# Engineer pack's phases: [] is the empty case — the gstack-learnings
+# IngestionSource is daemon-side, not a cycle phase.
+phases:
+  - extract_atoms
+  - synthesize_concepts
+
+# Union of creator + investor + engineer calibration domains. Same
+# explicit re-declaration rationale as phases — calibration_domains
+# aren't borrowed; the meta-pack declares the full set.
+#
+# Aggregator algorithms are the closed enum; domain names match the
+# per-pack declarations so the JSONB scorecard keys are stable across
+# active-pack switches (a user moving from gbrain-investor to
+# gbrain-everything keeps their deal_success scorecard intact).
+calibration_domains:
+  # From gbrain-creator:
+  - name: concept_themes
+    aggregator: cluster_summary
+    page_types:
+      - concept
+
+  # From gbrain-investor:
+  - name: deal_success
+    aggregator: scalar_brier
+    page_types:
+      - deal
+  - name: founder_evaluation
+    aggregator: scalar_brier
+    page_types:
+      - person
+  - name: market_call
+    aggregator: weighted_brier
+    page_types:
+      - thesis
+
+  # From gbrain-engineer:
+  - name: architecture_calls
+    aggregator: scalar_brier
+    page_types:
+      - code
+      - learning
+  - name: effort_estimates
+    aggregator: weighted_brier
+    page_types:
+      - project
+  - name: risk_assessment
+    aggregator: scalar_brier
+    page_types:
+      - project
+
+# Filing rules inherit through extends + borrow. No re-declaration needed —
+# registry merges parent + borrowed pack filing_rules.
+filing_rules: []
diff --git a/src/core/schema-pack/base/gbrain-investor.yaml b/src/core/schema-pack/base/gbrain-investor.yaml
new file mode 100644
index 000000000..ec1b0b1db
--- /dev/null
+++ b/src/core/schema-pack/base/gbrain-investor.yaml
@@ -0,0 +1,151 @@
+# gbrain-investor — investor/YC lens pack
+#
+# v0.41 lens packs wave. Declares the investor work surface that the user
+# (YC president) already runs every day across the wintermute agent + brain:
+#   - 501 investor profiles at brain/investors/
+#   - 19 deal memos at brain/investing/deals/
+#   - 5.3K companies + 24.6K people + 7.1K YC pages
+#   - 8 investor skills (yc-radar, yc-portfolio-health, sequoia-batch-bangers,
+#     investor-diligence, batch-picks-for-investor, etc.)
+#   - Fences already in use: ## Recommendation, ## Pre-mortem, ## Defensibility
+#     (6-8 moats), ## Founders, ## Product, ## Market / Customers, ## Traction,
+#     ## Team, ## Signals
+#
+# This pack consolidates the EXISTING primitives as pack-owned + adds a
+# bet-resolution lifecycle:
+#
+#   - `thesis` (NEW): investment thesis with thesis_text, key_bets[],
+#     market_view, vintage. Filed at investing/theses/{slug}.
+#
+#   - `bet_resolution_log` (NEW): outcome record for a thesis's bet. Bound
+#     to a take row via take_id, carries resolved_outcome + resolved_at +
+#     learned_pattern. Filed at investing/bets/{YYYY-MM}/{slug}.
+#
+# Calibration: declares 3 domains feeding the v0.41-widened
+# calibration_profile: deal_success (Brier over resolved deal-flagged
+# takes), founder_evaluation (Brier over person-flagged takes), market_call
+# (weighted Brier over thesis-flagged takes, weighted by take.confidence
+# because market calls' high-conviction-but-rare nature wants Brier scaled
+# by stake).
+#
+# Does NOT declare new cycle phases — investor work consumes the existing
+# extract_facts + propose_takes + grade_takes + calibration_profile loop.
+# The propose_takes phase populates take_domain_assignments rows at write
+# time from this pack's page_types → domain mapping (T10 wiring).
+#
+# Cron consolidation: existing wintermute crons (yc-radar-weekly,
+# yc-portfolio-health monthly, yc-oh-ingest daily) continue running on
+# their own schedules in wintermute — gbrain-investor doesn't displace
+# them, only declares their output types + calibration semantics. v0.42+
+# may migrate those crons too once their phase contracts stabilize.
+
+api_version: gbrain-schema-pack-v1
+name: gbrain-investor
+version: 1.0.0
+description: "Investor / YC president lens. Adds thesis + bet_resolution_log types to the deal/investor/company/person surface that already exists in gbrain-base. Declares deal_success / founder_evaluation / market_call calibration domains feeding the widened calibration_profile."
+gbrain_min_version: 0.41.0
+extends: gbrain-base
+
+# Borrow deal + person + company + yc from gbrain-base — they remain
+# base-owned (other packs may also use them) but this pack's calibration
+# domains reference them. No new declarations needed because borrow_from
+# just signals intent; the registry already merges types from the
+# extends chain.
+borrow_from:
+  - pack: gbrain-base
+    types:
+      - deal
+      - person
+      - company
+      - yc
+
+# Investor work uses the same takes_kinds as base (fact, take, bet, hunch).
+# The `bet` kind is the load-bearing one for this pack — bet_resolution_log
+# tracks outcomes for take rows of kind='bet'.
+# takes_kinds intentionally omitted (inherits from base).
+
+# Pack-specific page types. `deal` already exists in gbrain-base seed.
+# `thesis` and `bet_resolution_log` are net-new for v0.41.
+#
+# `investor` and `founder` (alias for person in deal context) are
+# deferred: investor pages are filed under investors/ but the type is
+# `person` today and changing it requires data migration. v0.42+ can
+# introduce them with proper migration.
+page_types:
+  - name: thesis
+    primitive: concept
+    path_prefixes:
+      - investing/theses/
+      - theses/
+    aliases: []
+    # extractable: true — theses contain claims that the LLM extractor
+    # can mine into facts (the thesis itself is a claim; sub-bets are
+    # claims). extract_facts walks them.
+    extractable: true
+    # expert_routing: false — theses don't surface in find_experts;
+    # founders + companies carry that weight.
+    expert_routing: false
+
+  - name: bet_resolution_log
+    primitive: temporal
+    path_prefixes:
+      - investing/bets/
+      - bets/
+    aliases: []
+    extractable: false
+    expert_routing: false
+
+# No new cycle phases. Investor work consumes the existing pipeline.
+phases: []
+
+# v0.41 T3: investor-flavored calibration domains. Each binds the closed
+# aggregator algorithm to the open domain name + page_types whose takes
+# feed this bucket. propose_takes (T10) populates take_domain_assignments
+# rows at write time from this mapping when this pack is active.
+calibration_domains:
+  - name: deal_success
+    # Standard Brier over resolved deal-attached binary takes
+    # (did this deal succeed? = take.resolved_outcome).
+    aggregator: scalar_brier
+    page_types:
+      - deal
+
+  - name: founder_evaluation
+    # Standard Brier over person-attached takes. The "how often I'm
+    # wrong about founders" signal.
+    aggregator: scalar_brier
+    page_types:
+      - person
+
+  - name: market_call
+    # Weighted Brier — market calls are rare-but-high-stakes; weighting
+    # by take.confidence means a misfired strong conviction costs more
+    # than a misfired weak hunch.
+    aggregator: weighted_brier
+    page_types:
+      - thesis
+
+# Filing rules — mirror wintermute's existing layout so the v0.41
+# greenfield migration (T7) lands pages in their canonical locations.
+filing_rules:
+  - kind: deal
+    directory: investing/deals/
+    examples:
+      - investing/deals/widget-co-pre-a-memo
+    description: "Investment memos. Pre-existing fences (## Recommendation, ## Pre-mortem, ## Defensibility, ## Founders, ## Product, ## Market / Customers, ## Traction, ## Team) carry through unchanged."
+  - kind: thesis
+    directory: investing/theses/
+    examples:
+      - investing/theses/ai-agents-2026
+      - investing/theses/hardware-renaissance
+    description: "Investment theses with thesis_text + key_bets[] + market_view + vintage frontmatter. Sub-bets resolve into bet_resolution_log entries via the take_id FK chain."
+  - kind: bet_resolution_log
+    directory: investing/bets/
+    examples:
+      - investing/bets/2026-04/widget-co-arr-trajectory
+    description: "Resolution records for thesis bets. Month-bucketed by resolution date. Frontmatter: bet_id (FK to thesis.key_bets), resolved_outcome (boolean), resolved_at (ISO date), learned_pattern (one-sentence takeaway). Populates the market_call calibration domain."
+  - kind: investor
+    directory: investors/
+    examples:
+      - investors/example-vc-fund
+    description: "Investor profiles (501 already extant). Filed flat under investors/. Page type stays `person` for now (data-migration deferral). v0.42+ may introduce dedicated `investor` page type."
diff --git a/src/core/schema-pack/index.ts b/src/core/schema-pack/index.ts
index e4fd7b462..9ab915f1d 100644
--- a/src/core/schema-pack/index.ts
+++ b/src/core/schema-pack/index.ts
@@ -16,6 +16,10 @@ export {
   parseSchemaPackManifest,
   computeManifestSha8,
   packIdentity,
+  // v0.41 T3 — calibration domain registry
+  AGGREGATOR_KINDS,
+  type AggregatorKind,
+  type CalibrationDomain,
 } from './manifest-v1.ts';
 
 export {
diff --git a/src/core/schema-pack/load-active.ts b/src/core/schema-pack/load-active.ts
index af9a7efff..cb62ab736 100644
--- a/src/core/schema-pack/load-active.ts
+++ b/src/core/schema-pack/load-active.ts
@@ -95,7 +95,20 @@ function defaultPackLocator(name: string): string | null {
   // v0.39 T8 — bundled packs registry. gbrain-base + gbrain-recommended
   // ship in src/core/schema-pack/base/. Add a new entry here to bundle
   // additional canonical packs.
-  const BUNDLED: ReadonlyArray<string> = ['gbrain-base', 'gbrain-recommended'];
+  //
+  // v0.41 T4 — lens packs join the bundle: creator (atoms + concepts +
+  // extract_atoms/synthesize_concepts phases), investor (theses + bet
+  // resolution + 3 calibration domains), engineer (gstack-learnings bridge
+  // + 3 calibration domains), everything (meta-pack stacking all three
+  // via extends + borrow_from). Each ships as a real YAML at base/<name>.yaml.
+  const BUNDLED: ReadonlyArray<string> = [
+    'gbrain-base',
+    'gbrain-recommended',
+    'gbrain-creator',
+    'gbrain-investor',
+    'gbrain-engineer',
+    'gbrain-everything',
+  ];
   if (BUNDLED.includes(name)) {
     // Resolve bundled YAML relative to this source file. Works in both
     // direct-bun execution and bun --compile binaries.
diff --git a/test/lens-pack-manifests.test.ts b/test/lens-pack-manifests.test.ts
new file mode 100644
index 000000000..1ec68c748
--- /dev/null
+++ b/test/lens-pack-manifests.test.ts
@@ -0,0 +1,247 @@
+// v0.41 T4 — bundled lens pack manifest smoke tests.
+//
+// One test file covers all 4 packs (creator, investor, engineer, everything)
+// because each test boils down to "manifest parses + declares the expected
+// shape." Splitting per-pack would 4x the boilerplate without adding signal.
+//
+// Pinned contracts:
+//   - All 4 YAMLs parse via parseSchemaPackManifest without error
+//   - Each pack registered in BUNDLED (loadPackManifestByName resolves)
+//   - Each pack declares the expected page_types, phases, calibration_domains
+//   - extends chain resolves through registry without depth error
+//   - gbrain-everything unions all three lens packs' contributions
+//   - Calibration domain aggregator is the closed AggregatorKind enum on every entry
+
+import { describe, test, expect } from 'bun:test';
+import { readFileSync, existsSync } from 'fs';
+import { join, dirname } from 'path';
+import { fileURLToPath } from 'url';
+import {
+  parseSchemaPackManifest,
+  parseYamlMini,
+  AGGREGATOR_KINDS,
+  type SchemaPackManifest,
+} from '../src/core/schema-pack/index.ts';
+
+const PACK_NAMES = [
+  'gbrain-creator',
+  'gbrain-investor',
+  'gbrain-engineer',
+  'gbrain-everything',
+] as const;
+
+const here = dirname(fileURLToPath(import.meta.url));
+const baseDir = join(here, '..', 'src', 'core', 'schema-pack', 'base');
+
+function loadPack(name: string): SchemaPackManifest {
+  const p = join(baseDir, `${name}.yaml`);
+  if (!existsSync(p)) {
+    throw new Error(`bundled pack not found at ${p}`);
+  }
+  const raw = readFileSync(p, 'utf-8');
+  const parsed = parseYamlMini(raw);
+  return parseSchemaPackManifest(parsed, { path: p });
+}
+
+describe('v0.41 T4: all 4 bundled lens packs parse cleanly', () => {
+  for (const name of PACK_NAMES) {
+    test(`${name}.yaml parses via parseSchemaPackManifest without error`, () => {
+      const pack = loadPack(name);
+      expect(pack.name).toBe(name);
+      expect(pack.version).toMatch(/^\d+\.\d+\.\d+$/);
+      expect(pack.api_version).toBe('gbrain-schema-pack-v1');
+    });
+  }
+});
+
+describe('v0.41 T4: bundled registry includes lens packs', () => {
+  test('load-active.ts BUNDLED array source includes the 4 lens pack names', () => {
+    const loadActiveSrc = readFileSync(
+      join(here, '..', 'src', 'core', 'schema-pack', 'load-active.ts'),
+      'utf-8',
+    );
+    for (const name of PACK_NAMES) {
+      expect(loadActiveSrc).toContain(`'${name}'`);
+    }
+  });
+});
+
+describe('v0.41 T4: gbrain-creator manifest shape', () => {
+  const pack = loadPack('gbrain-creator');
+
+  test('extends gbrain-base', () => {
+    expect(pack.extends).toBe('gbrain-base');
+  });
+
+  test('declares atom page type (NEW to base)', () => {
+    const atom = pack.page_types.find((p) => p.name === 'atom');
+    expect(atom).toBeDefined();
+    expect(atom?.primitive).toBe('concept');
+    expect(atom?.path_prefixes).toContain('atoms/');
+    expect(atom?.extractable).toBe(false); // leaf node, not source for further extraction
+    expect(atom?.expert_routing).toBe(false);
+  });
+
+  test('declares extract_atoms + synthesize_concepts phases', () => {
+    expect(pack.phases).toContain('extract_atoms');
+    expect(pack.phases).toContain('synthesize_concepts');
+  });
+
+  test('declares concept_themes calibration domain with cluster_summary aggregator', () => {
+    const themes = pack.calibration_domains.find((d) => d.name === 'concept_themes');
+    expect(themes).toBeDefined();
+    expect(themes?.aggregator).toBe('cluster_summary');
+    expect(themes?.page_types).toContain('concept');
+  });
+
+  test('filing rules for atom + concept include canonical paths', () => {
+    const atomRule = pack.filing_rules.find((r) => r.kind === 'atom');
+    expect(atomRule?.directory).toBe('atoms/');
+    const conceptRule = pack.filing_rules.find((r) => r.kind === 'concept');
+    expect(conceptRule?.directory).toBe('concepts/');
+  });
+});
+
+describe('v0.41 T4: gbrain-investor manifest shape', () => {
+  const pack = loadPack('gbrain-investor');
+
+  test('extends gbrain-base + borrows deal/person/company/yc', () => {
+    expect(pack.extends).toBe('gbrain-base');
+    const borrowEntry = pack.borrow_from.find((b) => b.pack === 'gbrain-base');
+    expect(borrowEntry).toBeDefined();
+    expect(borrowEntry?.types).toEqual(expect.arrayContaining(['deal', 'person', 'company', 'yc']));
+  });
+
+  test('declares thesis + bet_resolution_log page types', () => {
+    const thesis = pack.page_types.find((p) => p.name === 'thesis');
+    expect(thesis).toBeDefined();
+    expect(thesis?.primitive).toBe('concept');
+    expect(thesis?.extractable).toBe(true);
+
+    const bet = pack.page_types.find((p) => p.name === 'bet_resolution_log');
+    expect(bet).toBeDefined();
+    expect(bet?.primitive).toBe('temporal');
+  });
+
+  test('declares NO new cycle phases (consumes existing pipeline)', () => {
+    expect(pack.phases).toEqual([]);
+  });
+
+  test('declares 3 calibration domains (deal_success + founder_evaluation + market_call)', () => {
+    const names = pack.calibration_domains.map((d) => d.name).sort();
+    expect(names).toEqual(['deal_success', 'founder_evaluation', 'market_call']);
+  });
+
+  test('every calibration_domain aggregator is in the closed AggregatorKind enum', () => {
+    for (const d of pack.calibration_domains) {
+      expect(AGGREGATOR_KINDS).toContain(d.aggregator);
+    }
+  });
+
+  test('market_call uses weighted_brier (high-conviction-rare-event semantics)', () => {
+    const mc = pack.calibration_domains.find((d) => d.name === 'market_call');
+    expect(mc?.aggregator).toBe('weighted_brier');
+  });
+
+  test('filing rules cover deal + thesis + bet_resolution_log + investor', () => {
+    const kinds = pack.filing_rules.map((r) => r.kind).sort();
+    expect(kinds).toEqual(['bet_resolution_log', 'deal', 'investor', 'thesis']);
+  });
+});
+
+describe('v0.41 T4: gbrain-engineer manifest shape', () => {
+  const pack = loadPack('gbrain-engineer');
+
+  test('extends gbrain-base + borrows code/project', () => {
+    expect(pack.extends).toBe('gbrain-base');
+    const borrowEntry = pack.borrow_from.find((b) => b.pack === 'gbrain-base');
+    expect(borrowEntry?.types).toEqual(expect.arrayContaining(['code', 'project']));
+  });
+
+  test('declares ONLY learning page type (D8-C bridge-only)', () => {
+    expect(pack.page_types.length).toBe(1);
+    expect(pack.page_types[0].name).toBe('learning');
+    expect(pack.page_types[0].primitive).toBe('annotation');
+  });
+
+  test('declares NO new cycle phases (gstack bridge is daemon-side IngestionSource)', () => {
+    expect(pack.phases).toEqual([]);
+  });
+
+  test('declares 3 calibration domains (architecture_calls + effort_estimates + risk_assessment)', () => {
+    const names = pack.calibration_domains.map((d) => d.name).sort();
+    expect(names).toEqual(['architecture_calls', 'effort_estimates', 'risk_assessment']);
+  });
+
+  test('effort_estimates uses weighted_brier (small-vs-big estimate scaling)', () => {
+    const ee = pack.calibration_domains.find((d) => d.name === 'effort_estimates');
+    expect(ee?.aggregator).toBe('weighted_brier');
+  });
+
+  test('every calibration_domain aggregator is in the closed AggregatorKind enum', () => {
+    for (const d of pack.calibration_domains) {
+      expect(AGGREGATOR_KINDS).toContain(d.aggregator);
+    }
+  });
+});
+
+describe('v0.41 T4: gbrain-everything meta-pack shape', () => {
+  const pack = loadPack('gbrain-everything');
+
+  test('extends gbrain-investor (chain head)', () => {
+    expect(pack.extends).toBe('gbrain-investor');
+  });
+
+  test('borrows from gbrain-creator + gbrain-engineer', () => {
+    const borrowedPacks = pack.borrow_from.map((b) => b.pack).sort();
+    expect(borrowedPacks).toEqual(['gbrain-creator', 'gbrain-engineer']);
+  });
+
+  test('borrows atom from creator and learning from engineer', () => {
+    const creatorBorrow = pack.borrow_from.find((b) => b.pack === 'gbrain-creator');
+    expect(creatorBorrow?.types).toContain('atom');
+    const engineerBorrow = pack.borrow_from.find((b) => b.pack === 'gbrain-engineer');
+    expect(engineerBorrow?.types).toContain('learning');
+  });
+
+  test('declares NO own page_types (everything via extends + borrow)', () => {
+    expect(pack.page_types).toEqual([]);
+  });
+
+  test('explicitly re-declares phases from creator (borrow_from does NOT borrow phases)', () => {
+    expect(pack.phases).toEqual(['extract_atoms', 'synthesize_concepts']);
+  });
+
+  test('explicitly unions ALL 7 lens calibration domains', () => {
+    const names = pack.calibration_domains.map((d) => d.name).sort();
+    expect(names).toEqual([
+      'architecture_calls',
+      'concept_themes',
+      'deal_success',
+      'effort_estimates',
+      'founder_evaluation',
+      'market_call',
+      'risk_assessment',
+    ]);
+  });
+
+  test('every meta-pack calibration_domain aggregator is in the closed enum', () => {
+    for (const d of pack.calibration_domains) {
+      expect(AGGREGATOR_KINDS).toContain(d.aggregator);
+    }
+  });
+
+  test('aggregator selection matches per-pack declarations (cross-pack consistency)', () => {
+    const byName = Object.fromEntries(pack.calibration_domains.map((d) => [d.name, d.aggregator]));
+    // From investor
+    expect(byName.deal_success).toBe('scalar_brier');
+    expect(byName.market_call).toBe('weighted_brier');
+    expect(byName.founder_evaluation).toBe('scalar_brier');
+    // From creator
+    expect(byName.concept_themes).toBe('cluster_summary');
+    // From engineer
+    expect(byName.architecture_calls).toBe('scalar_brier');
+    expect(byName.effort_estimates).toBe('weighted_brier');
+    expect(byName.risk_assessment).toBe('scalar_brier');
+  });
+});