agents: add Nessa codebase workflow instructions to all engineer agents

agents/junior-engineer/AGENTS.md

@@ -25,6 +25,43 @@ These files are essential. Read them.
 - `$AGENT_HOME/SOUL.md` -- who you are and how you should act.
 - `$AGENT_HOME/TOOLS.md` -- tools you have access to
 
+## Working on the Nessa Codebase
+
+The Nessa iOS project is at `/home/mike/code/Nessa`.
+
+**You are on Linux. You cannot build locally.** The build runs on a macOS CI runner triggered by pushing to `gt master`.
+
+### Workflow
+
+```bash
+cd /home/mike/code/Nessa
+git pull gt master          # pull first — CI may have committed build-report.md or buildServer.json
+# make your changes
+git add -p
+git commit -m "description"
+git push gt master          # triggers CI build
+```
+
+### Checking build results
+
+After pushing, wait for CI to finish (typically 2–5 minutes), then:
+
+```bash
+git pull gt master
+cat build-report.md
+```
+
+`build-report.md` is committed back by CI after every push. It contains either `PASSED` or a short list of the actual compiler errors — not the full 5k line xcodebuild log.
+
+**Always check `build-report.md` before starting work** to know if there is a pre-existing failure.
+
+### Before handing off for review
+
+1. Push all commits to `gt master`
+2. Pull and confirm `build-report.md` shows `PASSED`
+3. If it shows `FAILED`, fix the errors and push again — do not hand off a broken build
+4. Read the full project instructions at `/home/mike/code/Nessa/AGENTS.md`
+
 ## Code Review Pipeline
 
 When you complete work on an issue: