feat(trekresearch): add Phase 4.5 dimension discovery and amend Independence rule

commands/trekresearch.md

@@ -391,6 +391,34 @@ other agents — the value of Gemini is independence.
   small = halved, medium/large = default
 - convention-scanner: medium+ codebases only (50+ files)
 
+## Phase 4.5 — Dimension discovery
+
+**Skip this phase entirely unless `phase_signal_result.effort == 'high'`.**
+
+Phase 4 retrieves more than the interview knew to ask for. This phase mines
+that surplus: findings that were **retrieved but unintegrated** — material an
+agent surfaced that no interview dimension claims.
+
+1. **Mine.** Walk the Phase-4 agent results and collect findings that map to
+   no existing dimension.
+2. **Rerank.** Order candidates by relevance to the research question **and**
+   dissimilarity to the dimensions already on the list. A candidate that
+   restates an existing dimension is not a discovery.
+3. **Augment under the existing ceiling.** Append candidates to the dimension
+   list only while the **whole** list (interview + discovered) stays at or
+   below `maxDimensions: 8` (`settings.json:16`). The ceiling is **not**
+   raised here, so the documented 3–8 dimension range stays true and the
+   README prose about it stays untouched. If the interview already produced 8
+   dimensions, this phase discovers nothing and says so.
+4. **Record the baseline.** Keep the interview-derived count as
+   `dimensions_baseline` so the discovered delta is machine-readable against
+   the final `dimensions` (Phase 8 stats).
+
+Every outbound query generated from a discovered dimension passes
+`query-privacy-gate.mjs` before it leaves the machine — see the per-turn
+protocol in Phase 5. That gate is the compensating control for the
+Independence crossing this phase makes (see Hard rules → Independence).
+
 ## Phase 5 — Targeted follow-ups
 
 Review all agent results. Identify knowledge gaps — dimensions where findings
@@ -727,6 +755,16 @@ Low effort: inline research only, no agent swarm (existing
 - **Sources required:** Every claim must cite a source. No unsourced findings.
 - **Independence:** Do not pre-bias external agents with local findings or vice versa.
   Triangulate AFTER independent research.
+  **Amended (v5.10) for Phase 4.5:** dimension discovery deliberately crosses this
+  rule. Its candidate dimensions are mined from the Phase-4 result set, which
+  contains output from the five local codebase agents, so a discovered dimension
+  can carry local context into an external query. The crossing is bounded to
+  Phase 4.5 and the Phase 5 loop it feeds, it never applies to the initial
+  external swarm (which stays blind to local findings), and the compensating
+  control is `query-privacy-gate.mjs`: every outbound query is inspected before
+  it leaves the machine, with a hard-block tier for secret-shaped strings that no
+  operator flag can override. Triangulation still happens AFTER independent
+  research.
 - **Graceful degradation:** If MCP tools are unavailable (Tavily, Gemini, MS Learn),
   proceed with available tools and note limitations in brief metadata.
 - **Cost:** Model resolution at Agent-spawn sites is a three-layer fallback: