fix(homecore-ui): resolve code-review findings — SSRF guard, CORS/trace coverage, §6 honesty, crash guards

Addresses the high-effort review of PR #1082:
- SECURITY: cal_proxy rejects path-traversal/confused-deputy SSRF (`.`/`..`
  segments, backslash, %2e%2e/%2f, absolute) on raw+decoded forms → 400,
  before attaching the server-side calibration bearer.
- CORRECTNESS: /api/homecore/* + /api/cal/* now covered by the shared CORS
  allowlist (build_cors_layer, exported from homecore-api) + TraceLayer —
  previously merged outside router()'s layers (no CORS, no tracing).
- §6 HONESTY (no fabricated data): dashboard renders '—' for null metrics
  (not "null%"/"null°C"); cogs Hailo pill reflects the REAL appliance probe
  (not hardcoded "connected"); room anomaly threshold passed through / null,
  not a fabricated 0.5.
- ROBUSTNESS: cogs asArray(hef) guards a non-array manifest field; calibration
  progress guards target<=0 (no NaN%/Infinity%); restart clears the poll timer.
- CLEANUP: mock.js is now a cached DYNAMIC import (demo-only) — never bundled
  in production (§2.2).
- New ui/tests/unit-fixes.mjs pins the above; ADR-131 + CHANGELOG updated.

Co-Authored-By: claude-flow <ruv@ruv.net>

v2/crates/homecore-api/src/app.rs

@@ -42,7 +42,11 @@ pub fn router(state: SharedState) -> Router {
         .with_state(state)
 }
 
-fn build_cors_layer() -> CorsLayer {
+/// Build the audited CORS allowlist layer (HC-05). Exposed so the
+/// integration binary can apply the SAME allowlist to routes merged in
+/// outside `router()` (e.g. the ADR-131 BFF gateway), instead of leaving
+/// `/api/homecore/*` and `/api/cal/*` with no CORS coverage at all.
+pub fn build_cors_layer() -> CorsLayer {
     let raw = std::env::var("HOMECORE_CORS_ORIGINS").ok();
     let origins: Vec<HeaderValue> = match raw {
         Some(v) if !v.trim().is_empty() => v

v2/crates/homecore-api/src/lib.rs

@@ -7,7 +7,7 @@ pub mod state;
 pub mod tokens;
 pub mod ws;
 
-pub use app::{router, AppState};
+pub use app::{build_cors_layer, router, AppState};
 pub use error::{ApiError, ApiResult};
 pub use state::SharedState;
 pub use tokens::LongLivedTokenStore;