release(v5.10.1): drop gemini-bridge from the pipeline; correct the T1 §6 PoC status

gemini-bridge is dropped by operator directive (three repetitions). The drop is
permanent, not a wait-for-SDK-upgrade state, so the change clears every LIVE
surface that could still steer a run toward the agent and leaves the historical
record alone.

Live surfaces cleared: agents/gemini-bridge.md deleted; trekresearch (bridge
launch block, --local help, high-effort always-on pair, stats record,
degradation list), trekplan, trekbrief, research-orchestrator (mode table,
agent table, prompting block, summary line), README (feature prose, mode table,
agent prose, mermaid EXTERNAL node, conditional legend, optional-MCP
requirement, --local section), CLAUDE.md, settings.json (the whole
trekresearch.geminiBridge block), both templates, architecture.md,
command-modes.md.

trekplan high-effort Adversarial Pass 2 now degrades EXPLICITLY: it emits its
section with status "unavailable, skipped" instead of failing or vanishing. A
high-effort plan carrying no Pass 2 marker is indistinguishable from one whose
Pass 2 crashed, which is the failure mode this wording exists to prevent.

gemini_used is deliberately KEPT as a vestigial trekresearch stats field pinned
to false. Removing it would break the observability export schema for existing
consumers, and the directive was about the agent, not the field.

Not touched: CHANGELOG history and the measurement/decision docs keep their
gemini references. They record what a past version did or what was measured
then; rewriting them is the same defect class as bumping a version string
inside a measurement doc.

Driven test-first. Five new pins in tests/lib/doc-consistency.test.mjs, verified
RED before the edits, including a KNOWN-POSITIVE CONTROL asserting the
historical records still DO carry gemini references — so the empty result on
live surfaces is a measurement and not a broken query (Verifiseringsloven
ansikt 4). Agent inventory 24 -> 23 (20 spawnable + 3 orchestrator reference
docs); the <example>-block floor moves 34 -> 32 because an agent legitimately
left the inventory, not because examples went missing from a surviving one.

Docs: docs/T1-cc26-delegated-orchestration.md §8 item 3 claimed both the §6
synthesis-agent PoC and the §5 bake-off were "designed but unbuilt". That was
written in S7 and falsified the same afternoon by S12, which ran the §6 PoC and
recorded Δ main-context (faithful flow) = 0.0%, NEGATIVE. The stale wording is
what caused the settled PoC to be re-ordered as new work on 2026-09-02, so it is
struck rather than deleted and §6 gained a RUN AND DECLINED status block. The
finding is structural, not stochastic: Phase 5 spawns the exploration swarm
foreground (trekplan.md:158,338-341), so the outputs are already resident in
main before Phase 7 — delegating only the Phase-7 digest evicts nothing.

Also measured 2026-09-03 (CC 2.1.259): claude -p --output-format stream-json
runs on subscription auth with no ANTHROPIC_API_KEY and now emits a
subagent_stats block, so S12's environment-block premise is half stale. Recorded
in §8 item 4. It lowers the cost of §5; it changes nothing about §6.

Suite 1041 (1039/0/2), up from 1036 by exactly the five tests added.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -4,7 +4,43 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
-## Unreleased
+## v5.10.1 — 2026-09-03 — gemini-bridge dropped; fail-closed review verdicts
+
+### Removed
+
+- **`gemini-bridge` is dropped from the pipeline (operator directive).** The
+  agent file is deleted and every live surface that could still steer a run
+  toward it is cleared: `commands/trekresearch.md` (the Bridge-agent launch
+  block, the `--local` help text, the high-effort always-on pair, the stats
+  record, the graceful-degradation list), `commands/trekplan.md`,
+  `commands/trekbrief.md`, `agents/research-orchestrator.md` (mode table,
+  agent table, prompting block, summary line), `README.md` (feature prose, mode
+  table, agent prose, the mermaid EXTERNAL node, the `* = conditional` legend,
+  the optional-MCP requirement, the `--local` section), `CLAUDE.md`,
+  `settings.json` (the whole `trekresearch.geminiBridge` block),
+  `templates/research-brief-template.md` (the *Gemini Second Opinion* section
+  and the sources-table `gemini` type), `templates/trekbrief-template.md`,
+  `docs/architecture.md`, `docs/command-modes.md`.
+- **`/trekplan` high-effort Adversarial Pass 2 degrades explicitly.** It now
+  emits a `## Adversarial Pass 2 (v5.1.1 high-effort)` section whose status
+  reads **"unavailable, skipped"**, rather than failing or vanishing: a
+  high-effort plan carrying no Pass 2 marker is indistinguishable from one whose
+  Pass 2 crashed. `/trekresearch` high effort forces only `contrarian-researcher`
+  always-on, which remains the complete adversarial coverage.
+- **Not removed:** `gemini_used` survives as a vestigial `/trekresearch` stats
+  field pinned to `false`. Dropping it would break the observability export
+  schema for existing consumers, and no consumer asked for that.
+- Agent inventory: **24 → 23 files** (20 spawnable + 3 orchestrator reference
+  docs; `synthesis-agent` still dormant). Counts reconciled in `README.md` and
+  `CLAUDE.md`; the `<example>`-block floor in
+  `tests/lib/agent-frontmatter.test.mjs` moves 34 → 32 because an agent
+  legitimately left the inventory — not because examples went missing from a
+  surviving one.
+- Pinned by 5 new tests in `tests/lib/doc-consistency.test.mjs`, including a
+  **known-positive control** asserting the historical records *still do* carry
+  gemini references — so the empty result on live surfaces is a measurement and
+  not a broken query. CHANGELOG entries and measurement/decision docs keep their
+  references deliberately: they record what a past version did.
 
 ### Fixed
 
@@ -35,6 +71,29 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ### Docs
 
+- **T1 §6 PoC status corrected — it was already run and declined.**
+  `docs/T1-cc26-delegated-orchestration.md` §8 item 3 still claimed both the §6
+  synthesis-agent PoC and the §5 full bake-off were "designed but unbuilt". That
+  was written in S7 and falsified the same afternoon by S12, which ran the §6
+  PoC and recorded **Δ main-context (faithful flow) = 0.0%, NEGATIVE**
+  (`docs/T1-synthesis-poc-results.md`; reproduce with
+  `node scripts/synthesis-measure.mjs`). The stale wording caused the settled
+  PoC to be re-ordered as new work on 2026-09-02, so it is struck rather than
+  deleted and §6 gained an explicit **RUN AND DECLINED** status block. The
+  finding is structural, not stochastic: `/trekplan` Phase 5 spawns the
+  exploration swarm **foreground** (`commands/trekplan.md:158,338-341`), so the
+  6–10 outputs are already resident in main before Phase 7 begins — delegating
+  only the Phase-7 digest returns on top of them and evicts nothing. A saving
+  needs the Phase-5 delivery moved off-main, which is §5.
+- **§5's environment premise updated (measured 2026-09-03, CC 2.1.259).** S12
+  recorded the live bake-off as blocked for want of an `ANTHROPIC_API_KEY`;
+  `claude -p --output-format stream-json` in fact runs on subscription auth with
+  no API key and now emits a `subagent_stats` block (spawned / max_depth /
+  refused) that did not exist in June — a ready-made classifier-interference
+  counter for §5's feasibility guard. S12's other blocker (the installed plugin
+  is the cache copy, so a repo-local agent is invisible to `claude -p`) stands
+  unmeasured. This changes nothing about the §6 verdict; it lowers the cost of §5.
+
 - **`/trekresearch --engine deep-research`: document the real version window.**
   Claude Code **2.1.218** changed `/deep-research` to start only when the operator
   invokes it; from there the Skill tool refuses a model invocation outright with