docs: add Gitea milestone tracking instructions to all phase docs

Each phase doc now includes:
- Milestone Tracking section linking to the corresponding Gitea milestone
- Checklist item in Completion Criteria to close the milestone
- Phase 7 also closes the Final: Porting Complete milestone (ID 8)

docs/plans/phases/phase-2-verification.md

@@ -21,6 +21,10 @@ proceeding to library mapping and porting.
 | Go source code | `golang/` (specifically `golang/nats-server/`) |
 | .NET ported version | `dotnet/` |
 
+## Milestone Tracking
+
+This phase corresponds to **Milestone 2** in [Gitea](https://gitea.dohertylan.com/dohertj2/natsnet/milestone/2). When starting this phase, verify the milestone is open. Assign relevant issues to this milestone as work progresses.
+
 ## Steps
 
 ### Step 1: Generate the summary report
@@ -265,6 +269,14 @@ Phase 2 is complete when ALL of the following are true:
 - [ ] `dependency ready` returns at least one item (the graph has valid roots).
 - [ ] Library mappings table contains all external imports.
 - [ ] `phase check 1` passes with all items except "All libraries mapped" checked.
+- [ ] Close the Phase 2 milestone in Gitea:
+  ```bash
+  curl -s -X PATCH "https://gitea.dohertylan.com/api/v1/repos/dohertj2/natsnet/milestones/2" \
+    -H "Content-Type: application/json" \
+    -H "Authorization: token $GITEA_TOKEN" \
+    -d '{"state":"closed"}'
+  ```
+  Or close it via the Gitea web UI at https://gitea.dohertylan.com/dohertj2/natsnet/milestone/2
 
 ## Troubleshooting