test(coverage): batch 5–8 — Rust unit tests toward 80% for 20 modules (#607)

* test(coverage): batch 5–8 — Rust unit tests toward 80% for 20 modules (#530)

Add 244 new unit tests across 20 modules to push line coverage from
75.06% → 75.70% overall. Modules improved:

- api/socket: 77% → 100%
- rpc/dispatch: 75% → 100%
- config/schema/channels: 77% → 100%
- composio/gmail/sync: 78% → 97%
- composio/notion/sync: 77% → 96%
- webhooks/router: 78% → 96%
- agent/hooks: 78% → 92%
- config/schema/proxy: 76% → 90%
- local_ai/device: 79% → 89%
- text_input/schemas: 73% → 89%
- agent/harness/interrupt: 76% → 88%
- billing/schemas: 79% → 87%
- screen_intelligence/schemas: 78% → 81%
- about_app/types, health/schemas, app_state/schemas,
  core/types, config/schema/identity_cost, cron/scheduler

Tests cover: schema catalog integrity, param deserialization,
serde roundtrips, helper functions, edge cases, error paths.
All 3974 tests pass.

* test(coverage): batch 9–10 — browser_open, update_memory_md, credentials profiles, cost tracker (#530)

Add 53 new tests across 4 more modules:
- browser_open: IPv4/IPv6 private ranges, host matching, normalize_domain edges
- update_memory_md: empty file, section creation, unknown action, param validation
- credentials/profiles: token expiry, CRUD operations, active profile management
- cost/tracker: budget warnings, monthly exceeded, model stats aggregation

All 4027 tests pass.

* test(coverage): batch 11–12 — channels schemas, conversation store (#530)

Add 33 new tests:
- channels/controllers/schemas: per-function input validation, param
  deserialization, helper coverage
- memory/conversations/store: thread lifecycle (create, delete, idempotent),
  multi-thread, empty/nonexistent thread, purge empty store

All 4060 tests pass.

src/api/socket.rs

@@ -12,3 +12,53 @@ pub fn websocket_url(http_or_https_base: &str) -> String {
     };
     format!("{}/socket.io/?EIO=4&transport=websocket", ws_base)
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn converts_https_to_wss() {
+        let url = websocket_url("https://api.tinyhumans.ai");
+        assert_eq!(
+            url,
+            "wss://api.tinyhumans.ai/socket.io/?EIO=4&transport=websocket"
+        );
+    }
+
+    #[test]
+    fn converts_http_to_ws() {
+        let url = websocket_url("http://localhost:3000");
+        assert_eq!(
+            url,
+            "ws://localhost:3000/socket.io/?EIO=4&transport=websocket"
+        );
+    }
+
+    #[test]
+    fn passes_through_unknown_scheme() {
+        let url = websocket_url("ftp://example.com");
+        assert_eq!(
+            url,
+            "ftp://example.com/socket.io/?EIO=4&transport=websocket"
+        );
+    }
+
+    #[test]
+    fn strips_trailing_slash() {
+        let url = websocket_url("https://api.tinyhumans.ai/");
+        assert_eq!(
+            url,
+            "wss://api.tinyhumans.ai/socket.io/?EIO=4&transport=websocket"
+        );
+    }
+
+    #[test]
+    fn strips_multiple_trailing_slashes() {
+        let url = websocket_url("https://api.tinyhumans.ai///");
+        assert_eq!(
+            url,
+            "wss://api.tinyhumans.ai/socket.io/?EIO=4&transport=websocket"
+        );
+    }
+}