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>

docs/T1-cc26-delegated-orchestration.md

@@ -135,6 +135,17 @@ reused.
 
 ## 6. Cheaper PoC (audit-recommended, preferred over the full bake-off)
 
+> **STATUS: RUN AND DECLINED (S12, 2026-06-18) — do not re-order as new work.**
+> Result: **Δ main-context (faithful flow) = 0.0%**, NEGATIVE against the 15% keep-floor.
+> Full method, fixtures and BASE-sweep: `docs/T1-synthesis-poc-results.md`;
+> reproduce with `node scripts/synthesis-measure.mjs`.
+> The finding is **structural, not stochastic**, so re-running it cannot change the number:
+> Phase 5 spawns the exploration swarm **foreground** (`commands/trekplan.md:158,338-341` —
+> "foreground is the only mode as of v2.4.0"), 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 is reachable only by also moving Phase-5 delivery off-main —
+> which is §5, not §6. `agents/synthesis-agent.md` therefore ships **dormant**.
+
 Per `subagent-delegation-audit.md` §Recommendation, the lowest-risk way to test the delegation
 *premise* is **not** a wholesale orchestrator rewrite but **one narrow synthesis-agent**
 (intervention #1/#3): delegate only trekplan Phase 7 synthesis (the heaviest single inline read —
@@ -169,5 +180,17 @@ promising orchestration-substrate question and is untouched by this.
    only matters if a future nested pipeline approaches 5.
 2. Classifier behaviour for a *purposeful* swarm under `auto`/`bypassPermissions` is unverified
    (F4) — must be in the §5/§6 test matrix before any delegated spawn ships to a headless path.
-3. The §6 synthesis-agent PoC and the §5 full bake-off are both **designed but unbuilt** — ready
-   to run if CC-26 is greenlit toward delegation.
+3. ~~The §6 synthesis-agent PoC and the §5 full bake-off are both designed but unbuilt.~~
+   **CORRECTED 2026-09-03 (S95).** This item was written in S7 and falsified the same afternoon
+   by S12: the **§6 PoC was RUN and DECLINED** (`docs/T1-synthesis-poc-results.md` — Δ_faithful
+   = 0.0%, NEGATIVE). Only the **§5 full bake-off** remains unbuilt. The stale wording is what
+   caused the §6 PoC to be re-ordered as new work on 2026-09-02; it is struck rather than
+   deleted so the re-order has a traceable cause.
+4. **Environment premise updated (measured 2026-09-03, CC 2.1.259).** S12 recorded the live run
+   as environment-blocked for want of an `ANTHROPIC_API_KEY`. That half no longer holds:
+   `claude -p --output-format stream-json` runs on subscription auth with no API key and emits
+   per-turn `usage` plus 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 stands unmeasured: the installed plugin is the cache copy, so a
+   repo-local agent is invisible to `claude -p`. This changes nothing about the §6 verdict,
+   which is structural (see §6 status), and only lowers the cost of §5.