Phase 5: group-voice docs, onboarding runbook, CHORUS icon — v2.0.0-rc.1

The final phase of CHORUS-PLAN.md. Code- and doc-complete for group use;
rc pends live deployment at chorusapi.mpm.to.

- Repo README rewritten for CHORUS: group model (schema 5), concurrency
  posture, configuration, baked-build onboarding, layout, testing, 2.0
  version history (ECHO history referenced at the fork tag).
- Operator→member voice sweep across SKILL.md (incl. the trigger
  description, now group-aware), all references, 8 command docs, plugin
  README; member preferences / semantic layer / triage guidance describe
  the group model.
- docs/ONBOARDING.md: member runbook — vault stand-up, per-member config,
  bake, deliver, self-onboarding first load, norms, offboarding.
- docs/USAGE.md rewritten as the member usage guide.
- New icon: chorus-icon.svg + 1024/512/64 PNGs (three voices, one center).
- Removed ECHO-era assets (icons, spec PDF, perf briefs); ECHO planning
  docs retired to docs/history/. All preserved at echo-fork-point.
- eval/README documents test_multimember.py. Manifest -> 2.0.0-rc.1;
  rebuilt chorus-memory.plugin.

Verified: routing-sync, 25/25 unit, scaffold, 5 mock e2e suites,
run_eval metrics green.

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

CHANGELOG.md

@@ -1,5 +1,32 @@
 # Changelog
 
+## 2.0.0-rc.1 — Phase 5 (docs, onboarding, icon) — plan complete
+
+The last phase of the CHORUS conversion plan. The plugin is code- and doc-complete
+for group use; rc status pends only live deployment at `chorusapi.mpm.to`.
+
+### Changed
+- **Group-voice docs everywhere.** Repo README fully rewritten for CHORUS (group
+  model, concurrency posture, configuration, baked-build onboarding, schema-5
+  layout, testing, 2.0 version history — ECHO history now referenced at the fork
+  tag). SKILL.md description + remaining prose, all references, commands, and the
+  plugin README swept operator→member; each member's `preferences.md` section,
+  the semantic layer, and the triage routing guidance now describe the group model.
+- `docs/USAGE.md` rewritten as the member usage guide (automatic behaviors,
+  commands incl. `--author`/`--all-members`, group etiquette, troubleshooting).
+
+### Added
+- **`docs/ONBOARDING.md`** — the member-onboarding runbook: vault stand-up,
+  per-member config, `build.py --bake-key`, delivery, self-onboarding first load,
+  first-session norms, offboarding = key rotation, troubleshooting table.
+- **CHORUS icon** — `chorus-icon.svg` (+ 1024/512/64 PNGs): three voices (teal /
+  violet / amber) radiating waves around one shared center.
+
+### Removed
+- ECHO-era assets: echo icons, the ECHO spec PDF and performance briefs, and the
+  ECHO planning docs (`TODO-1.6.md`, `ROADMAP-2.0.md` → `docs/history/`). All
+  remain at the `echo-fork-point` tag and in `jason/echo`.
+
 ## 2.0.0-alpha.4 — Phase 4 (shared-write hardening + group lenses)
 
 ### Added