docs: link completion criteria to Gitea issues and add issue tracking guidance

- Created 52 Gitea issues across milestones 1-7, one per completion criterion
- Each criterion now links to its corresponding issue ([#N](url) format)
- Milestone Tracking sections updated with Issue Updates subsection:
  when/how to comment, close issues via CLI or web UI
- Phases 4-7 criteria converted from plain bullets to checkbox format

docs/plans/phases/phase-3-library-mapping.md

@@ -24,6 +24,23 @@ returns an empty list and every import has a documented .NET migration path.
 
 This phase corresponds to **Milestone 3** in [Gitea](https://gitea.dohertylan.com/dohertj2/natsnet/milestone/3). When starting this phase, verify the milestone is open. Assign relevant issues to this milestone as work progresses.
 
+### Issue Updates
+
+Each completion criterion has a corresponding Gitea issue. Update issues as you work:
+
+- **Starting a criterion**: Add a comment noting work has begun
+- **Blocked**: Add a comment describing the blocker
+- **Complete**: Close the issue with a comment summarizing the result (e.g., counts, verification output)
+
+Close issues via CLI:
+```bash
+curl -s -X PATCH "https://gitea.dohertylan.com/api/v1/repos/dohertj2/natsnet/issues/{N}" \
+  -H "Content-Type: application/json" \
+  -H "Authorization: token $GITEA_TOKEN" \
+  -d '{"state":"closed"}'
+```
+Or close via the Gitea web UI.
+
 ## Steps
 
 ### Step 1: List all unmapped libraries
@@ -249,13 +266,13 @@ For each mapping, consider:
 
 Phase 3 is complete when ALL of the following are true:
 
-- [ ] `library suggest` returns "All libraries have been mapped!"
-- [ ] Every entry in `library list` shows status `mapped` or `verified`.
-- [ ] Each mapping includes a `--package` (the NuGet package or BCL assembly),
+- [ ] [#30](https://gitea.dohertylan.com/dohertj2/natsnet/issues/30) `library suggest` returns "All libraries have been mapped!"
+- [ ] [#21](https://gitea.dohertylan.com/dohertj2/natsnet/issues/21) Every entry in `library list` shows status `mapped` or `verified`.
+- [ ] [#22](https://gitea.dohertylan.com/dohertj2/natsnet/issues/22) Each mapping includes a `--package` (the NuGet package or BCL assembly),
       a `--namespace` (the .NET namespace to use), and `--notes` (migration
       guidance).
-- [ ] `phase check 1` shows all items checked including "All libraries mapped".
-- [ ] A mapping report has been exported for reference.
+- [ ] [#23](https://gitea.dohertylan.com/dohertj2/natsnet/issues/23) `phase check 1` shows all items checked including "All libraries mapped".
+- [ ] [#24](https://gitea.dohertylan.com/dohertj2/natsnet/issues/24) A mapping report has been exported for reference.
 - [ ] Close the Phase 3 milestone in Gitea:
   ```bash
   curl -s -X PATCH "https://gitea.dohertylan.com/api/v1/repos/dohertj2/natsnet/milestones/3" \