Update docs, changelog, examples, and add ADRs for v1.2

- Add v1.1.0 and v1.2.0 changelog entries
- Add exclude field to config reference and example config
- Add ADRs documenting all major design decisions
- Fix step numbering in reverse_sync()
- Fix action.yml to copy VERSION file
- Add dist/ and .env to .gitignore
- Use refs/tags/ format for Nix flake tag refs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,32 @@
 # Changelog
 
+## 1.2.0
+
+### Features
+
+- **File exclusion**: `exclude` config field removes files/directories from the subrepo at the josh-proxy transport layer. Patterns are embedded inline in the josh-proxy URL using `:exclude[::pattern,...]` syntax — no extra files to generate or commit.
+- **Filter change reconciliation**: When the josh filter changes (e.g., adding/removing exclude patterns), josh-sync automatically creates a reconciliation merge commit that connects old and new histories. No manual reset or force-push required.
+- **Tree comparison guard**: Reverse sync now compares subrepo tree to josh-filtered tree before checking commit log. Skips immediately when trees are identical, avoiding false positives from reconciliation merge history.
+- **Unrelated histories detection**: Forward sync detects when histories are unrelated (no common ancestor) and falls back to reconciliation instead of creating a useless conflict PR.
+
+### Fixes
+
+- Pre-v1.2 state compatibility: When upgrading from v1.0/v1.1 (no `josh_filter` stored in state), the old filter is derived from `subfolder` so reconciliation triggers correctly.
+- Reconciliation merge parent order: Josh-filtered history is always first parent so josh-proxy can follow first-parent traversal back to the monorepo.
+- Reverse sync `--ancestry-path` flag prevents old subrepo history from leaking through reconciliation merge parents.
+- PR body `\n` now renders as actual newlines instead of literal text.
+- Conflict result no longer updates sync state (added `continue` to skip state write).
+- `action.yml` now copies VERSION file for correct `--version` output in CI.
+- `.gitignore` now includes `dist/` and `.env`.
+
+## 1.1.0
+
+### Features
+
+- **`onboard` command**: Interactive, resumable workflow for importing existing subrepos into the monorepo. Walks through: prerequisites check, import (creates PRs), wait for merge, reset (pushes josh-filtered history). Checkpoint/resume at every step.
+- **`migrate-pr` command**: Migrates open PRs from an archived subrepo to the new one. Supports interactive selection, `--all` flag, and specific PR numbers. Uses `git apply --3way` for resilient patch application.
+- **Onboard state tracking**: Stored on the `josh-sync-state` branch at `<target>/onboard.json`. Tracks step progress, import PR numbers, reset branches, and migrated PRs.
+
 ## 1.0.0
 
 Initial release. Extracted from [private-monorepo-example](https://code.itkan.io/pe/private-monorepo-example) into a standalone reusable library.