chore(cleanup): R-b R1 — Voyage's own stats, events and OTel export removed

Removes Voyage's measurement, statistics and export apparatus (decision 189;
condition 175 met in step 1) and the R-a leftovers: lib/stats/, lib/exporters/,
the otel-export and post-bash-stats hooks, yardstick, end-state and comparison
gates, synthesis-measure, gold-scorer, docs/observability.md,
examples/observability/, docs/T1-cc26-delegated-orchestration.md and their
tests and fixtures. The six command stats phases and the /trekexecute
main-merge event blocks go; intent-approval --stamp no longer emits
brief-approved. README and docs point to Claude Code's own OpenTelemetry.

Files removed: 52. Files edited: 37.
npm test: 2930 tests (2928 pass / 0 fail / 2 skipped) before, 2600 tests
(2598 pass / 0 fail / 2 skipped) after. removed-surfaces group R1 green.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture.md

@@ -10,10 +10,9 @@ Imported from `CLAUDE.md` via pointer.
 - `lib/parsers/{plan-schema,manifest-yaml,arg-parser,jaccard,finding-id}.mjs` — pure parsers (no I/O), unit-tested. `manifest-yaml` extended in v3.4.0 with additive `skip_commit_check` + `memory_write` flags (forward-compat: unknown keys ignored)
 - `lib/review/{rule-catalogue,plan-review-dedup}.mjs` — version-pinned rule catalogue (17 keys) + Phase 9 inline dedup helpers (v3.4.0)
 - `lib/review/{verdict-gate,engine-findings,recurrence}.mjs` — the review gate (K7: 0 ALLOW, or WARN with every counting MAJOR answered · 1 BLOCK · 2 never green), Claude Code `/code-review` + `/security-review` findings → reviewer payload, recurring finding classes → operator-approved project-memory lines (review_version 1.2); `lib/review/fill-finding-ids.mjs` computes the coordinator's `@@ID_<n>@@` placeholders over `(file, line, rule_key)`; `lib/validators/brief-review-stamp.mjs` lets `/trekplan` skip a brief review `/trekbrief` already ran on the same text
-- `lib/stats/event-emit.mjs` — single-source stats event emitter for named lifecycle events (`brief-approved`, the main-merge gate and its answer, `user_input`) (v3.4.0)
 - `lib/validators/{brief,research,plan,progress,session-state}-validator.mjs` — schema validators with CLI shims (`node lib/validators/X.mjs --json <path>`)
 - `lib/validators/architecture-discovery.mjs` — drift-WARN external-contract discovery for `architecture/overview.md`
-- `lib/util/research-loop-cap.mjs` — stateful, **default-off** turn budget for the `/trekresearch` bounded conversation loop. `allowTurn()` derives the used-turn count from its own append-only JSONL ledger; it never asks the caller how many turns it has spent, because a cap that does is not a cap. Each grant first claims a turn **slot** with `O_EXCL` under `trekresearch-loop-claims/`, so the bound survives several callers deciding at once — counting the ledger and then appending is read-then-write, and Phase 4.5/5 can spawn several agents in one message. Budget = `TREKRESEARCH_MAX_CONV_TURNS` (default `3`, invalid values fall back to `3`) × `maxDimensions` (8, `MAX_TOTAL_DIMENSIONS`). **Default-off:** grants 0 unless `VOYAGE_STORM_ENABLED=1`, which is also the second condition on Phase 4.5's skip-guard (that phase does not call this module): unset, **both** STORM phases are inert. `resolveDataRoot()` is the single root for everything the loop writes — `CLAUDE_PLUGIN_DATA` when the harness sets it, `~/.claude/voyage` when it does not (it is empty in the Bash tool's process env, which is where the loop actually runs); the cap hook resolves through the same function, so writer and reader cannot disagree. A ledger that cannot be **written** denies the turn, and one that exists but cannot be **read** denies it too — only `ENOENT` counts as zero turns spent, that being the legitimate first-turn state (fail-closed — the opposite of `event-emit.mjs`, which is telemetry and must never block). The exported `readLedger()` is the single counting rule; the cap hook calls it rather than keeping a private copy. `checkDimensionCeiling()` is the reader for the OTHER axis of the bounded-cost NFR — the size of the whole dimension list after Phase 4.5 discovery — against the same `MAX_TOTAL_DIMENSIONS`, so the two axes cannot enforce different numbers for one ceiling; an unreadable count is rejected, not waved through. CLI shim, two modes: `--run-id ID --dimension D --effort E` (budget gate) and `--check-dimensions N` (ceiling, no run id/effort/flag required since Phase 4.5 never calls the budget gate)
+- `lib/util/research-loop-cap.mjs` — stateful, **default-off** turn budget for the `/trekresearch` bounded conversation loop. `allowTurn()` derives the used-turn count from its own append-only JSONL ledger; it never asks the caller how many turns it has spent, because a cap that does is not a cap. Each grant first claims a turn **slot** with `O_EXCL` under `trekresearch-loop-claims/`, so the bound survives several callers deciding at once — counting the ledger and then appending is read-then-write, and Phase 4.5/5 can spawn several agents in one message. Budget = `TREKRESEARCH_MAX_CONV_TURNS` (default `3`, invalid values fall back to `3`) × `maxDimensions` (8, `MAX_TOTAL_DIMENSIONS`). **Default-off:** grants 0 unless `VOYAGE_STORM_ENABLED=1`, which is also the second condition on Phase 4.5's skip-guard (that phase does not call this module): unset, **both** STORM phases are inert. `resolveDataRoot()` is the single root for everything the loop writes — `CLAUDE_PLUGIN_DATA` when the harness sets it, `~/.claude/voyage` when it does not (it is empty in the Bash tool's process env, which is where the loop actually runs); the cap hook resolves through the same function, so writer and reader cannot disagree. A ledger that cannot be **written** denies the turn, and one that exists but cannot be **read** denies it too — only `ENOENT` counts as zero turns spent, that being the legitimate first-turn state (fail-closed). The exported `readLedger()` is the single counting rule; the cap hook calls it rather than keeping a private copy. `checkDimensionCeiling()` is the reader for the OTHER axis of the bounded-cost NFR — the size of the whole dimension list after Phase 4.5 discovery — against the same `MAX_TOTAL_DIMENSIONS`, so the two axes cannot enforce different numbers for one ceiling; an unreadable count is rejected, not waved through. CLI shim, two modes: `--run-id ID --dimension D --effort E` (budget gate) and `--check-dimensions N` (ceiling, no run id/effort/flag required since Phase 4.5 never calls the budget gate)
 - `lib/validators/query-privacy-gate.mjs` — gates **every** outbound research query before it leaves the machine; the hard-block tier (secret-shaped strings) is not operator-overridable, so a query that trips it must be reformulated rather than forced through. CLI shim: `node lib/validators/query-privacy-gate.mjs "<query>"`
 
 Wiring points (replaces previous prose-grep instructions):
@@ -32,19 +31,17 @@ Doc-consistency test at `tests/lib/doc-consistency.test.mjs` pins agent-table co
 
 `hooks/scripts/session-title.mjs` (UserPromptSubmit, CC v2.1.94+) sets `sessionTitle` to `voyage:<command>:<slug>` for voyage-command invocations. Helps parallel sessions identify themselves in process lists.
 
-`hooks/scripts/post-bash-stats.mjs` (PostToolUse, CC v2.1.97+) appends `duration_ms` for each Bash call into `${CLAUDE_PLUGIN_DATA}/trekexecute-stats.jsonl`. Useful for finding long-running verify or checkpoint commands.
-
 `hooks/scripts/pre-agent-cap.mjs` (PreToolUse on `WebSearch|WebFetch|Task`) enforces the `/trekresearch` Phase 5 loop bound in the harness, so the cap is not merely prose the model is asked to obey. It counts spent turns read-only from the append-only ledger `research-loop-cap.mjs` writes, through that module's own exported `readLedger()`. It denies (exit 2) once the budget **gate has denied a turn** — the primitive records its denials as tombstones, and the tombstone is the boundary rather than the count, because `allowTurn()` appends before the turn runs and so the final granted turn already shows `budget` records. A ledger showing more granted turns than the budget denies too, as a backstop. Being in scope but unable to count the ledger also denies: a budget control that cannot count must not grant. Scope key = `session_id` + a marker file only the loop writes (`<resolveDataRoot()>/trekresearch-loop-scope/<session_id>.json`, the same root the ledger uses); without a marker the hook allows unconditionally, which is what keeps a globally-wired `PreToolUse` hook from over-blocking unrelated sessions. Stale markers auto-reset on a TTL and `VOYAGE_DISABLE_CAP_HOOK=1` is the kill switch. Defence in depth only — `lib/util/research-loop-cap.mjs` must stay correct if the hook stops firing (see `docs/spike-pretooluse-subagent-reach.md`).
 
 `hooks/scripts/post-compact-flush.mjs` (PostCompact event, v3.4.0) re-injects `.session-state.local.json` after context compaction so multi-session work survives a compaction boundary. Companion to `pre-compact-flush.mjs` (which writes the state file before compaction); together they form the rehydrate cycle that keeps `/trekcontinue` reliable across long-running multi-session work.
 
 ## Architecture
 
-**Brief:** 7-phase workflow: Parse mode → Create project dir → Phase 3 completeness loop (section-driven, no question cap) → Phase 3.5 per-phase effort dialog (v5.1) → Phase 4 draft/review/revise with `brief-reviewer` as stop-gate (max 3 iterations; gate = all dimensions ≥ 4 and research plan = 5) → Finalize (`brief.md` on pass, or `brief_quality: partial` on cap/force-stop) → Manual/auto opt-in → Stats. Always interactive. Auto mode runs research + plan inline in the main context (v2.4.0).
+**Brief:** 7-phase workflow: Parse mode → Create project dir → Phase 3 completeness loop (section-driven, no question cap) → Phase 3.5 per-phase effort dialog (v5.1) → Phase 4 draft/review/revise with `brief-reviewer` as stop-gate (max 3 iterations; gate = all dimensions ≥ 4 and research plan = 5) → Finalize (`brief.md` on pass, or `brief_quality: partial` on cap/force-stop) → Manual/auto opt-in. Always interactive. Auto mode runs research + plan inline in the main context (v2.4.0).
 
 **Phase 3.5 (v5.1) — adaptive-depth signals:** Between Phase 3 completeness exit and Phase 4 draft, the operator commits an effort level (`low | standard | high`) and an optional `model` (`sonnet | opus | fable`) per downstream phase (`research`, `plan`, `execute`, `review`) via 4 tier-coupled `AskUserQuestion` calls. The choices land in `brief.md` frontmatter as `phase_signals:` (a list of `{phase, effort?, model?}` entries) when committed, or `phase_signals_partial: true` when the operator force-stops. `brief_version: 2.1` activates the **sequencing gate**: validator emits `BRIEF_V51_MISSING_SIGNALS` if a 2.1-versioned brief lacks both fields. Downstream commands surface a friendly hint pointing back to `/trekbrief` — enforcement is validator-only. Composition is documented prose in each downstream command's `## Composition rule (v5.1)` section: `brief.phase_signals[phase] > profile.phase_models[phase]`. The brief signal wins per-phase when present; the profile fills gaps. `effort == low` activates each command's existing `--quick`-equivalent code-path (`/trekexecute` low effort = one session at a time). High-effort behavior is deferred to v5.1.1 per brief Non-Goal.
 
-**Research:** Foreground workflow (v2.4.0): Parse mode → Interview → Parallel research swarm (5 local + 4 external + 1 bridge, spawned from main context) → Follow-ups → Triangulation → Synthesis + brief → Stats. With `--project`, writes to `{dir}/research/NN-slug.md`.
+**Research:** Foreground workflow (v2.4.0): Parse mode → Interview → Parallel research swarm (5 local + 4 external + 1 bridge, spawned from main context) → Follow-ups → Triangulation → Synthesis + brief. With `--project`, writes to `{dir}/research/NN-slug.md`.
 
 **Plan:** Foreground workflow (v2.4.0): Parse mode (validate brief input) → Codebase sizing → Brief review (`brief-reviewer`) → Parallel exploration (6-8 agents, spawned from main context) → Deep-dives → Synthesis (with architecture-note cross-reference if present) → Planning → Adversarial review (`plan-critic` + `scope-guardian`) → Present/refine → Handoff. With `--project`, writes to `{dir}/plan.md` and auto-detects `{dir}/architecture/overview.md` (produced by an opt-in upstream architect plugin if installed; not bundled).
 
@@ -87,7 +84,7 @@ No code-level dependency between plugins — the contract is filesystem-level on
 
 ### Primitives per step (decision matrix)
 
-Which native Claude Code primitive each pipeline step runs on today, and the alternatives that were considered and where they landed. Companion to *Delegate the engine, keep the policy* above; the decision record lives in `docs/T1-cc26-delegated-orchestration.md`. The orchestration runs inline in the session, not in a delegated orchestrator agent, because the swarm's results end in the main context anyway (the orchestrator reference docs are removed).
+Which native Claude Code primitive each pipeline step runs on today, and the alternatives that were considered and where they landed. Companion to *Delegate the engine, keep the policy* above. The orchestration runs inline in the session, not in a delegated orchestrator agent, because the swarm's results end in the main context anyway (the orchestrator reference docs are removed).
 
 | Step | Primitive today (production) | Alternatives considered (status) |
 |---|---|---|
@@ -97,7 +94,7 @@ Which native Claude Code primitive each pipeline step runs on today, and the alt
 | **execute** | Inline step loop; multi-session via `git worktree` + session orders the user runs, wave by wave; deterministic manifest audit | CC `TaskCreate`/`TodoWrite` for progress/resume (insufficient — carries no step status / attempts / SHA / drift → own typed `progress.json` contract) |
 | **review** | Inline parallel reviewers (no cross-feed) → `review-coordinator` Judge | **Workflow** substrate for Phase 5–6 (bake-off POSITIVE: +4.4 % tokens / +54 % wall-time → shipped opt-in, since removed; wholesale substrate swap declined) |
 | **continue** | Inline reads `.session-state.local.json` → zero-confirm resume | CC `--resume` (transcript replay, not typed work-state → insufficient) |
-| **cross-cutting** | 8 hook scripts: `pre-bash` + `pre-write` guards, `pre-agent-cap` loop-bound enforcement, `post-bash` stats, `session-title`, `pre-`/`post-compact` flush, **`Stop`→OTEL** export | — |
+| **cross-cutting** | 6 hook scripts: `pre-bash` + `pre-write` guards, `pre-agent-cap` loop-bound enforcement, `session-title`, `pre-`/`post-compact` flush | — |
 
 ¹ MCP per research agent: `docs-researcher` → Microsoft Learn + Tavily · `community-`/`security-`/`contrarian-researcher` → Tavily (+ WebSearch/WebFetch). Graceful degradation when an MCP server is absent.
 
@@ -123,26 +120,6 @@ Legacy paths (still work without `--project`):
 - Session orders: `.claude/trekplan-sessions/{slug}/orders.md` (`--decompose`) and `orders/` (`/trekexecute` Phase 2.6: one order per session, `wave.json` while a wave awaits its sessions, `merged-waves.json`, and each session's archived `wave-W-session-N.progress.json`)
 - Progress: `{plan-dir}/.trekexecute-progress-{slug}.json`
 
-Stats:
-- Brief stats: `${CLAUDE_PLUGIN_DATA}/trekbrief-stats.jsonl`
-- Plan stats: `${CLAUDE_PLUGIN_DATA}/trekplan-stats.jsonl`
-- Exec stats: `${CLAUDE_PLUGIN_DATA}/trekexecute-stats.jsonl`
-- Research stats: `${CLAUDE_PLUGIN_DATA}/trekresearch-stats.jsonl`
-- Continue stats: `${CLAUDE_PLUGIN_DATA}/trekcontinue-stats.jsonl`
-
-The Bash tool env carries no `CLAUDE_PLUGIN_DATA`. Brief, plan and execute
-stats are written by `lib/stats/stats-append.mjs`, which falls back to
-`~/.claude/plugins/data/voyage-ktg-plugin-marketplace/`, the directory
-`scripts/yardstick.mjs` reads. `/trekexecute`'s lifecycle events go through
-`lib/stats/event-emit.mjs`, which resolves the same directory. A failed write
-is reported, not skipped. The research, review and continue stats phases still
-name the variable in prose only.
-A brief record also carries `order_id`, `order_claimed_at` and `order_reason`:
-the coord-queue order the run is working on, added by the writer from the
-queue's claimed orders (`lib/stats/claimed-order.mjs`), never by the model.
-`scripts/yardstick.mjs` joins its `use` number on `order_id`; the three fields
-are never exported.
-
 ## Terminology
 
 - **Task brief** — produced by `/trekbrief`. Declares intent, goal, and research plan. Drives planning.