fix(pricing): add Sonnet 5 and Fable 5 to the canonical chat-pricing table (#2799)

claude-sonnet-5 and claude-fable-5 are GA Anthropic models, but neither
was in CANONICAL_PRICING. A brain routing a tier to them (e.g.
models.tier.reasoning = anthropic:claude-sonnet-5) ran with cost
telemetry blind on that tier: canonicalLookup missed, the budget meter
logged BUDGET_METER_NO_PRICING and disabled the gate, and cost views
under-reported spend.

- model-pricing.ts: anthropic:claude-sonnet-5 at $3/$15 and
  anthropic:claude-fable-5 at $10/$50. Sonnet 5's launch intro discount
  ($2/$10 through 2026-08-31) is deliberately not modeled — the table
  carries standard rates so estimates stay conservative and the entry
  needs no time-bombed edit when the promo lapses.
- takes-quality-eval/pricing.ts: claude-sonnet-5 added to the curated
  SUPPORTED_MODELS allowlist (a likely judge override). Fable 5 stays
  out — priced for warn-only consumers, not a budgeted-eval panel model.
- model-pricing.test.ts: pin tests for both rows, matching the existing
  Opus 4.8/4.7 pattern. Drift guards iterate the table; no changes.

All derived views (ANTHROPIC_PRICING bare view -> budget-tracker,
batch-projection, budget-meter) pick the rows up automatically.

Co-authored-by: Paolo Belcastro <p3ob7o@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

src/core/model-pricing.ts

@@ -52,11 +52,18 @@ export interface ModelPricing {
  */
 export const CANONICAL_PRICING: Record<string, ModelPricing> = {
   // ── Anthropic ──────────────────────────────────────────────────────────
+  // Fable 5: Anthropic's top tier, above Opus. $10 in / $50 out.
+  'anthropic:claude-fable-5':             { input: 10.00, output: 50.00 },
   // Opus 4.x: $5 in / $25 out. 4.8 (released 2026-05-28) shares 4.7's
   // per-token rate — closes gbrain#1819.
   'anthropic:claude-opus-4-8':            { input:  5.00, output: 25.00 },
   'anthropic:claude-opus-4-7':            { input:  5.00, output: 25.00 },
   'anthropic:claude-opus-4-6':            { input:  5.00, output: 25.00 },
+  // Sonnet 5 (released 2026-06-29): same $3/$15 sticker as 4.6. The launch
+  // intro discount ($2/$10 through 2026-08-31) is deliberately NOT modeled —
+  // the table carries standard rates so estimates stay conservative and
+  // don't need a time-bombed edit when the promo lapses.
+  'anthropic:claude-sonnet-5':            { input:  3.00, output: 15.00 },
   'anthropic:claude-sonnet-4-6':          { input:  3.00, output: 15.00 },
   // Haiku 4.5 — both the dateless canonical id and the dated snapshot.
   'anthropic:claude-haiku-4-5':           { input:  1.00, output:  5.00 },

src/core/takes-quality-eval/pricing.ts

@@ -37,6 +37,7 @@ const SUPPORTED_MODELS = [
   'openai:gpt-5.5',
   'anthropic:claude-opus-4-8',
   'anthropic:claude-opus-4-7',
+  'anthropic:claude-sonnet-5',
   'anthropic:claude-sonnet-4-6',
   'anthropic:claude-haiku-4-5',
   'google:gemini-1.5-pro',

test/model-pricing.test.ts

@@ -43,6 +43,14 @@ describe('CANONICAL_PRICING — table integrity', () => {
     expect(CANONICAL_PRICING['anthropic:claude-opus-4-7']).toEqual({ input: 5.0, output: 25.0 });
   });
 
+  test('Sonnet 5 present at $3/$15 (standard rate, intro discount not modeled)', () => {
+    expect(CANONICAL_PRICING['anthropic:claude-sonnet-5']).toEqual({ input: 3.0, output: 15.0 });
+  });
+
+  test('Fable 5 present at $10/$50', () => {
+    expect(CANONICAL_PRICING['anthropic:claude-fable-5']).toEqual({ input: 10.0, output: 50.0 });
+  });
+
   test('Gemini 2.0 Flash reconciled to $0.10/$0.40; legacy alias agrees', () => {
     expect(CANONICAL_PRICING['google:gemini-2.0-flash']).toEqual({ input: 0.1, output: 0.4 });
     expect(CANONICAL_PRICING['google:gemini-2-flash']).toEqual(