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>

docs/history/ECHO-TODO-1.6.md

@@ -0,0 +1,63 @@
+# echo-memory — v1.6 TODO
+
+> Working list for the next minor release. Started 2026-07-03, right after 1.5.1
+> shipped. **Add findings from 1.5.x live testing to the "Surfaced in testing"
+> section as they come up** — that's what this doc is for.
+
+## 1. Migrate the eight slash commands to the skills format
+
+The installer flags the plugin's `commands/` directory as the legacy format
+("Both formats work — consider migrating to skills/*/SKILL.md"). Confirmed against
+the official docs (code.claude.com/docs/en/skills.md, plugins.md):
+
+- **Non-breaking.** `commands/echo-save.md` → `skills/echo-save/SKILL.md` keeps the
+  invocation name: `/echo-save` works identically. No deprecation date on `commands/`;
+  this is future-proofing, not a fire.
+- **Do it for the features, not the notice:**
+  - [ ] `allowed-tools` per skill — pre-authorize the resolved `python3 "$ECHO" …`
+        invocations so `/echo-load`, `/echo-health`, `/echo-recall` stop prompting
+        (1.4.2 hand-broadened two commands; the skill format does this properly).
+  - [ ] `disable-model-invocation: true` on the write-heavy entry points
+        (`/echo-sweep`, `/echo-triage`) so only the operator triggers them; leave the
+        read-side ones model-invocable.
+  - [ ] De-duplicate the CoWork `$ECHO` path-resolution block currently copy-pasted
+        into all eight command bodies — each skill folder can carry a shared snippet.
+  - [ ] `argument-hint` carries over as-is; `$ARGUMENTS` substitution unchanged.
+- [ ] Verify a migrated build installs cleanly on desktop **and** in a CoWork session
+      before deleting `commands/` (deleting the legacy dir is a 2.0 item —
+      see `ROADMAP-2.0.md`; in 1.6 both may coexist).
+
+## 2. plugin.json completeness (from the old MAINTENANCE checklist)
+
+- [ ] Add `homepage` / repository URL — now decided: `https://git.alwisp.com/jason/echo`.
+
+## 3. Vault follow-ups (noticed during the 1.5.0 dead-link cleanup)
+
+Three of the 27 unwrapped "dead" links were actually **typos pointing at real notes**;
+they were unwrapped per instruction but repointing them would restore real graph edges:
+
+- [ ] `projects/active/forgerunner.md` + `_agent/sessions/2026-06-29-2200-forgerunner-v010-ship.md`:
+      "Gitea CI Docker jobs run on the host label" → the decision
+      `decisions/by-date/2026-06-29-gitea-ci-docker-jobs-run-on-the-host-lab.md` ("lab", not "label").
+- [ ] `projects/active/mpm-brand-voice.md`: "Message Point Media (MPM)" ×3 → the company
+      note `resources/companies/mpm.md` (or whatever is canonical for MPM).
+
+## 4. Surfaced in 1.5.x testing
+
+*(add items here as the new plugin gets real use)*
+
+- [ ] **Lint blind spot: retired dirs masked by the leaf-README route** (found 2026-07-03).
+      `archive/` and `_agent/outputs/` are retired/unrouted pre-0.6 leftovers that survived
+      in the live vault holding only their seed READMEs — and the permissive `leaf-readme`
+      route (`^(.+/)?README\.md$`) matches first, so `vault_lint` never flagged them.
+      Fix: in the path-membership check, test the *directory* against retired/unknown
+      patterns even when the only file in it is a README (e.g. evaluate `dirname(path) + "/"`
+      against retired patterns before letting `leaf-readme` absolve the file), or drop the
+      seed-README exemption inside retired trees. Add a lint test seeding
+      `archive/notes/README.md` → must flag `retired-path`.
+      *Related learning (same cleanup, 2026-07-03):* the REST API **cannot delete
+      directories** — removing a folder's last file orphans the empty folder on disk
+      (the REST listing 404s, falsely reading as gone; Obsidian still shows it — manual
+      deletion required). Documented in `references/api-reference.md` › Deleting Files
+      and in the vault's `resources/references/obsidian-local-rest-api.md`. Any future
+      "remove retired tree" guidance must include the manual folder-cleanup step.