docs: update Forgejo docs with tag mode E2E results

- Add E2E Test Results section with validated capabilities
- Document git ref API difference (refs vs ref) in Known Limitations
- Document user display name 403 fallback
- Add git ref lookup row to API differences table
- Add claude.yml workflow to CI workflows section
- Remove outdated "not yet E2E tested" note from tag mode

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

docs/forgejo.md

@@ -108,6 +108,7 @@ On Forgejo, there is no OIDC token exchange with Anthropic. The action uses the
 | **GitHub MCP server** | `ghcr.io/github/github-mcp-server` included | Skipped — GitHub-specific                                           |
 | **CI/Actions MCP**    | Full GitHub Actions API                     | Works via Octokit REST + `GITHUB_API_URL`                           |
 | **Permission check**  | `getCollaboratorPermissionLevel()`          | `repos.get()` fallback (workflow tokens lack collaborator endpoint) |
+| **Git ref lookup**    | `git.getRef()` (`/git/ref/heads/...`)       | `repos.getBranch()` (`/git/refs` is plural on Forgejo)              |
 
 ### Bun Installation
 
@@ -132,7 +133,11 @@ All other inputs work identically on both platforms. See the [Usage Guide](./usa
 
 ## Included CI Workflows
 
-This fork includes three Forgejo-native workflows in `.forgejo/workflows/`:
+This fork includes four Forgejo-native workflows in `.forgejo/workflows/`:
+
+### `claude.yml` — Tag Mode (@claude Mentions)
+
+Responds to `@claude` mentions on issues, PR review comments, and PR reviews. Also triggers on issue assignment and label events. This is the main interactive workflow for using Claude on Forgejo.
 
 ### `ci.yml` — Tests, Formatting, Type Checking
 
@@ -200,9 +205,36 @@ All Forgejo changes follow the **early-return pattern** — platform-specific lo
 
 New upstream features that use GraphQL or GitHub-specific APIs won't automatically work on Forgejo. The Forgejo data fetcher (`src/forgejo/data/fetcher.ts`) would need REST equivalents added. The action will still run — features that depend on missing data will simply lack that context.
 
+## E2E Test Results
+
+Both execution modes have been validated end-to-end on a Forgejo instance (git.wxs.ro):
+
+| Mode           | Trigger                     | Status    | Details                                                                                                                                                                   |
+| -------------- | --------------------------- | --------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| **Agent mode** | `workflow_dispatch`         | Validated | Platform detection, token auth, Claude execution, output file — all green                                                                                                 |
+| **Tag mode**   | `issue_comment` (`@claude`) | Validated | Issue context (title + body) read correctly, platform detected as `forgejo`, tracking comment created with spinner then updated with response (31s), job link URL correct |
+
+### Tag Mode Verified Capabilities
+
+- `@claude` trigger phrase detected in issue comments
+- Issue body and title fully visible to Claude
+- Tracking comment created with progress spinner, then updated with final response
+- Forgejo job run URL correctly formatted in tracking comment
+- Branch creation works via `repos.getBranch()` API (Forgejo uses `/git/refs` not `/git/ref`)
+- Permission check passes via `repos.get()` fallback
+
+### Not Yet E2E Tested
+
+- PR review comment triggers (`pull_request_review_comment`)
+- PR review triggers (`pull_request_review`)
+- Label triggers (`issues` with `labeled` action)
+- Assignee triggers (`issues` with `assigned` action)
+- Branch creation + code changes from tag mode (issue asked a question, no code changes needed)
+
 ## Known Limitations
 
-- **Tag mode (issue/PR triggers)**: Code is wired but only agent mode (workflow_dispatch) has been E2E tested on Forgejo. Tag mode should work but hasn't been validated with real issue/PR webhooks yet.
+- **Git ref API**: Forgejo uses `/git/refs` (plural) instead of GitHub's `/git/ref` (singular). The action handles this by using `repos.getBranch()` on Forgejo for branch SHA lookups.
+- **User display name fetch**: `GET /users/{username}` returns 403 without `read:user` scope. Non-fatal — falls back to login name.
 - **`pull_request_target` event**: May not exist in Forgejo. The action degrades gracefully (maps to `pull_request`).
 - **GitHub MCP server**: The `ghcr.io/github/github-mcp-server` Docker image is GitHub-specific and is skipped on Forgejo.
 - **Commit signing**: SSH signing has not been tested on Forgejo. The `use_commit_signing` option (GitHub API signing) won't work since it uses GitHub's commit API.