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>

examples/josh-sync.yml

@@ -10,17 +10,19 @@ josh:
 targets:
   - name: "billing"
     subfolder: "services/billing"
-    josh_filter: ":/services/billing"
+    # josh_filter auto-derived as ":/services/billing" if omitted
     subrepo_url: "https://gitea.example.com/ext/billing.git"
     subrepo_auth: "https"
     branches:
       main: main
       develop: develop
     forward_only: []
+    exclude:                          # files excluded from subrepo (optional)
+      - ".monorepo/"                  # directory at subfolder root
+      - "**/internal/"                # directory at any depth
 
   - name: "auth"
     subfolder: "services/auth"
-    josh_filter: ":/services/auth"
     subrepo_url: "git@gitea.example.com:ext/auth.git"
     subrepo_auth: "ssh"
     # Per-target credential override (reads from $AUTH_SSH_KEY instead of $SUBREPO_SSH_KEY)
@@ -31,7 +33,6 @@ targets:
 
   - name: "shared-lib"
     subfolder: "libs/shared"
-    josh_filter: ":/libs/shared"
     subrepo_url: "https://gitea.example.com/ext/shared-lib.git"
     branches:
       main: main