docs: deduplicate, trim and resync the repo documentation

.github/ISSUE_TEMPLATE/bug_report.md

@@ -24,7 +24,7 @@ What you thought would happen.
 
 ## Actual behaviour
 
-What actually happened (error messages, screenshots, copied logs — please redact anything sensitive).
+What actually happened (error messages, screenshots, copied logs). Redact anything sensitive.
 
 ## Environment
 
@@ -35,4 +35,4 @@ What actually happened (error messages, screenshots, copied logs — please reda
 
 ## Anything else
 
-Workarounds you've found, related issues, hypotheses about the cause — all welcome but optional.
+Workarounds you've found, related issues, hypotheses about the cause. All optional.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -20,15 +20,7 @@ What else did you weigh, and why did you rule it out?
 
 ## Milestone fit
 
-Where does this fit on the roadmap?
-
-- [ ] v0.6: Phone-ready
-- [ ] v0.7: Collaboration & reviews
-- [ ] v1.0: Public v1
-- [ ] Refactor / hygiene (no version gating)
-- [ ] Unscheduled candidate
-
-See [`planning/next.md`](../../planning/next.md) for the milestone tables and the *Unscheduled candidates* section. Items in [`planning/roadmap.md`](../../planning/roadmap.md) → *Future considerations* carry a documented rationale and revisit trigger: check that your proposal isn't already covered there.
+Which roadmap milestone fits, if any? See [`planning/roadmap.md`](../../planning/roadmap.md) for the milestones and [`planning/next.md`](../../planning/next.md) for the open work, the *Refactors* and the *Unscheduled candidates*. Items in [`planning/roadmap.md`](../../planning/roadmap.md) → *Future considerations* carry a documented rationale and revisit trigger: check that your proposal is not already covered there.
 
 ## Anything else
 

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,5 +1,5 @@
 <!--
-Title: Conventional Commit format — `type(scope): subject`, subject starts lowercase.
+Title: Conventional Commit format, `type(scope): subject`, subject starts lowercase.
 Enforced by .github/workflows/pr-title.yml. Examples in CONTRIBUTING.md.
 -->
 
@@ -9,27 +9,26 @@ What this change does, in one to three sentences. Link the issue it closes (`Clo
 
 ## Why
 
-Why this is the right change — the user problem, the constraint, the trade-off. Skip if the summary already covers it.
+Why this is the right change: the user problem, the constraint, the trade-off. Skip if the summary already covers it.
 
 ## Doc-sync checklist
 
-CI hard-fails the PR if `docs/` AND `planning/` aren't both touched (the `docs-pairing` job in [`.github/workflows/ci.yml`](../.github/workflows/ci.yml)). The bullets below are the conventions human review still owns — tick what applies; if none apply, explain why in the description.
+CI fails the PR unless it touches both `docs/` and `planning/` (see [`CONTRIBUTING.md`](../CONTRIBUTING.md#doc-sync-rule) → *Doc-sync rule*). Human review owns the pairings below. Tick what applies; if none apply, explain why in the description.
 
 - [ ] Touched `backend/app/routers/**` → updated [`docs/api.md`](../docs/api.md)
 - [ ] Touched `backend/app/models/**` or `backend/alembic/versions/**` → updated [`docs/data-model.md`](../docs/data-model.md) (table block **and** ER diagram)
 - [ ] Touched `.github/workflows/**`, `backend/Dockerfile`, `backend/railway.json`, or `docker-compose.yml` → updated [`docs/engineering.md`](../docs/engineering.md)
-- [ ] Touched production code (`backend/app/**`, `frontend/src/**`, or a migration) → added a one-line entry under `## Unreleased` in [`CHANGELOG.md`](../CHANGELOG.md)
+- [ ] Touched production code (`backend/app/**`, `frontend/src/**`, or a migration) → added a one-line entry with the PR link under `## Unreleased` in [`CHANGELOG.md`](../CHANGELOG.md)
 - [ ] Tech-choice swap (not a routine version bump) → updated [`docs/engineering.md`](../docs/engineering.md)
-- [ ] Auth model, deployment URLs, env vars, or primary dev workflow change → updated [`AGENTS.md`](../AGENTS.md) **and** [`README.md`](../README.md)
-- [ ] Palette recipe / shared style constant in [`styles.ts`](../frontend/src/components/ui/styles.ts) → updated [`docs/design.md`](../docs/design.md) (*Orange palette recipe*)
-- [ ] Shipped item removed from [`planning/next.md`](../planning/next.md) (or briefly noted in the relevant macro)
+- [ ] Auth model, deployment URLs, env vars, or primary dev workflow change → updated [`docs/engineering.md`](../docs/engineering.md) (*Local environment*, *Deployment*) **and** [`README.md`](../README.md)
+- [ ] Palette recipe / shared style constant in [`styles.ts`](../frontend/src/components/ui/styles.ts) → updated [`docs/design.md`](../docs/design.md) (*Accent recipe*)
+- [ ] Shipped item removed from [`planning/next.md`](../planning/next.md)
 
 ## Test plan
 
-How you verified this. Include the commands you ran (`make test`, `npm run lint`, etc.) and, for UI changes, the flow you walked through in the browser.
+How you verified this. Include the commands you ran and, for UI changes, the flow you walked through in the browser.
 
-- [ ] `make test` passes locally
-- [ ] Frontend `npm test` + `npm run lint` + `npx tsc --noEmit` + `npm run build` pass
+- [ ] Ran the local CI commands in [`CONTRIBUTING.md`](../CONTRIBUTING.md#pull-request-flow) step 3
 - [ ] Manual check of the affected user flow (describe below)
 
 ## Notes for the reviewer