docs(voyage): S33 — reconcile agent inventory (21 spawnable + 3 reference docs) + record D1–D3 considered-and-kept

Balance-backlog S33 (DOC, non-breaking). The D1–D3 forks resolved conservatively
(balance-backlog-plan.md), collapsing the model + observability work into a
documentation record. Three deliverables, all doc-only, no code/frontmatter change:

- V35 (doc half): the "24 agents" headline is reconciled to its honest split —
  21 spawnable (one dormant: synthesis-agent, Δ≈0) + 3 orchestrator reference
  docs (planning-/research-/review-orchestrator document the inline /trek*
  workflow; not spawned). Each orchestrator header now declares itself a
  "reference document, not a spawnable capability". README + CLAUDE.md state the
  split; counts in the new pins are DERIVED from agents/ so they survive reword.
- D2 (V32 rationale): docs/observability.md gains a "Why direct export rather
  than a native collector" section — direct export keeps the path / SSRF /
  field-allowlist guards in audited in-process code (the S21 hardening) instead
  of re-hosting a collector; textfile mode remains the collector escape hatch.
- D3 (kept-opus): docs/voyage-vs-cc-balance-analysis.md §10 decision record —
  opus on V09 (glue), V35 (dormant), V11 (retrieval), V16 (mechanical), V08
  (researchers) was reconsidered for sonnet and KEPT (pin 40d8742 firm).

No agent frontmatter changed — tests/lib/agent-frontmatter.test.mjs is the
structural model source-of-truth and is untouched (diff is description-only:
model: opus + tools lists unchanged, no Agent tool granted). No Handover-1
change; no exporter/gemini-bridge removal. Non-breaking, no version bump.

tests/lib/doc-consistency.test.mjs: +5 S33 pins (inventory split derived from
agents/; synthesis-agent dormant; orchestrator relabel; observability D2
rationale; analysis-doc D1–D3 record). Tests 739 (737 pass / 2 skip / 0 fail),
bar `node --test`; `claude plugin validate` green (1 accepted warning).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LqBYc8Ltrk7LipyJmGxXiB

CLAUDE.md

@@ -53,6 +53,8 @@ Full flag reference for each command (modes, `--gates`, `--profile`, breaking ch
 | contrarian-researcher | opus | Counter-evidence, overlooked alternatives |
 | gemini-bridge | opus | Gemini Deep Research second opinion (conditional) |
 
+> **Inventory (S33 reconcile).** 24 agent files = **21 spawnable** (one of which, `synthesis-agent`, ships **dormant** — Δ≈0, wired to nothing, see `docs/T1-synthesis-poc-results.md`) **+ 3 orchestrator reference docs** (`planning-/research-/review-orchestrator` document the inline `/trek*` workflow; they are reference documentation, not spawnable capabilities). All 24 stay `model: opus` (operator pin `40d8742`); the glue/mechanical/retrieval/dormant roles (V09 gemini-bridge, V16 session-decomposer, V11 retrieval agents, V08 researchers, V35 synthesis) were reconsidered for a sonnet downgrade and **kept opus** — document-only, no frontmatter change (the decision record lives in `docs/voyage-vs-cc-balance-analysis.md` §10).
+
 > **Model & effort (CC 2.1.154+).** `opus` resolves to **Opus 4.8** (default reasoning effort `high`); `sonnet` to Sonnet 4.6. Select agents carry native `effort:` — retrieval agents (`task-finder`, `git-historian`, `dependency-tracer`, `architecture-mapper`) at `medium`, adversarial-reasoning agents (`plan-critic`, `risk-assessor`, `contrarian-researcher`, `review-coordinator`) at `high`. This native per-spawn **reasoning** effort is a different axis from brief `phase_signals.effort` (orchestration shape — which agents/passes run). See `docs/profiles.md` §Model & effort axes.
 
 ## Reference docs (read on demand)