feat(graceful-handoff)!: integrate with STATE.md continuity system (v3.0.0)

BREAKING: replace the NEXT-SESSION artifact + 3 hooks with a STATE.md-centric,
skill-only design. /graceful-handoff now overwrites the nearest STATE.md (with the
mandatory 👉 NESTE block) instead of writing a separate handover file.

- Remove hooks/ entirely: Stop auto-trigger (operator choice), SessionStart loader
  (redundant with global session-start.sh), statusLine hint (dead — user settings win).
- Invert the pipeline: the model writes STATE.md (only it has the context for 👉 NESTE);
  handoff-pipeline.mjs becomes a slim deterministic helper (--plan / --commit / --dry-run).
- Remote-aware policy: STATE.md tracked on private remotes, local-only (gitignored) on
  public/open mirrors. Authoritative signal: git check-ignore STATE.md.
- SKILL.md rewritten as the Session-Slutt ritual; dropped the Sonnet model pin.
- Docs (README, CLAUDE.md, CHANGELOG), plugin.json 2.1.0→3.0.0, .gitignore cleanup.
- Tests rewritten for --plan/--commit; no-`git add -A` regression preserved. 30/30 green.

Release-cut (tag v3.0.0 + catalog ref bump) pending — separate gated action.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019SiKr4c6GAzQH5n6E6f5NA

CHANGELOG.md

@@ -4,6 +4,28 @@ All notable changes to graceful-handoff are documented here.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## [3.0.0] - 2026-06-23
+
+### BREAKING
+
+- **Full integration with the STATE.md continuity system.** The plugin no longer writes its own `NEXT-SESSION-PROMPT.local.md` artifact. `/graceful-handoff` now overwrites the **nearest STATE.md** (cwd → repo root) with a complete state-of-play in the mandatory format — title + subtitle + a `## 👉 NESTE — START HER` block on top, then fixed sections and short history. STATE.md is the one continuity layer; local handover inventions (`NEXT-SESSION`, `HANDOVER.md`, `ROADMAP.md`) are gone.
+- **Inverted architecture: the model writes, the script assists.** Only the session model has the context to fill the `👉 NESTE` block meaningfully — a deterministic `git log` snapshot never could. `scripts/handoff-pipeline.mjs` is now a slim, deterministic STATE helper: `--plan` (resolve nearest STATE.md + classify remote + git facts, read-only), `--commit` (stage **only** STATE.md when tracked, plus explicit `--also` paths — never `git add -A`), `--dry-run`. It no longer renders artifacts.
+- **All three hooks removed.** The Stop auto-trigger, the statusLine hint, and the SessionStart auto-loader are deleted (`hooks/` is gone):
+  - *SessionStart loader* was redundant — the global `~/.claude/hooks/session-start.sh` already injects the nearest STATE.md.
+  - *statusLine* was dead code — a user's `~/.claude/settings.json` statusLine always wins over a plugin's, and it already shows context %.
+  - *Stop auto-trigger* would overwrite a good, model-written STATE.md with a poor snapshot. Removed in favour of a purely manual regime.
+- **Removed the `model: claude-sonnet-4-6` pin.** Writing a self-standing STATE.md is human-facing synthesis → the skill now inherits the session model (Opus-class quality).
+
+### Changed
+
+- **Remote-aware STATE policy.** STATE.md must never reach a public mirror. The helper classifies the `origin` remote (`github.com` or the `open/` Forgejo namespace → public → STATE local-only/gitignored; otherwise → private → STATE tracked). The authoritative commit signal is `git check-ignore STATE.md`; `remote_class` only drives a `leak_warning` when the two disagree.
+- SKILL.md is now the operationalised "Session Slutt" ritual: reach a natural stopping point → `--plan` → write STATE.md → `--commit` → push only inside the window → fixed closing line.
+- Tests rewritten around `--plan`/`--commit`; the no-`git add -A` regression guard is preserved. Hook tests removed.
+
+### Migration from v2.x
+
+No automatic migration. Reinstall to drop the hooks. `/graceful-handoff` now writes STATE.md instead of a NEXT-SESSION artifact; any stale `NEXT-SESSION-*.local.md` files can be deleted. STATE.md auto-loads at session start via the global hook — the plugin no longer ships its own loader.
+
 ## [2.1.0] - 2026-05-01
 
 ### Fixed