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>

chorus-memory.plugin.src/commands/chorus-reflect.md

@@ -7,7 +7,7 @@ Use the **chorus-memory** skill to run **session reflection** (H5). Scan this co
 things worth remembering across sessions, then propose them — don't write blindly.
 
 1. **Extract** durable items from the conversation: new facts, preferences, decisions,
-   commitments, people/companies/projects introduced, and anything the operator said to remember.
+   commitments, people/companies/projects introduced, and anything the member said to remember.
    Skip the ephemeral. Anchor relative dates on the conversation's `currentDate`.
 2. **Emit a JSON array** of proposals (one per item), each:
    `{"title","kind","body","aliases","tags","sources","confidence"}` — `kind` ∈
@@ -15,7 +15,7 @@ things worth remembering across sessions, then propose them — don't write blin
    working, skill, decision`; set `"inbox": true` when the home is genuinely unknown;
    `confidence` 0–1 (items below 0.6 are dropped — send those to the inbox instead).
    Write the array to a file with the Write tool (cross-platform; no heredoc).
-3. **Preview, then apply.** Dry-run first (writes nothing) and show the operator the plan; only
+3. **Preview, then apply.** Dry-run first (writes nothing) and show the member the plan; only
    apply after they confirm.
 
 ```bash