feat: Seeded acceptance-ready job data through the live API with determ…

- "scripts/s06-acceptance-data.sh"
- "scripts/s06-acceptance-data.test.sh"
- "README.md"
- ".gsd/KNOWLEDGE.md"
- ".gsd/DECISIONS.md"
- ".gsd/milestones/M001/slices/S06/tasks/T02-SUMMARY.md"

GSD-Task: S06/T02

.gsd/KNOWLEDGE.md

@@ -7,3 +7,4 @@
 - `dotnet test JobTrackerApi.Tests/JobTrackerApi.Tests.csproj --filter JobApplicationsFollowUpDraftTests` is now trustworthy again in this worktree after restoring the missing ASP.NET Core / Identity / xUnit test-project references in `JobTrackerApi.Tests/JobTrackerApi.Tests.csproj`; older task notes that require an isolated Docker harness are stale.
 - Running `npm --prefix job-tracker-ui start` alone is not enough for browser UAT in this worktree: the frontend calls `http://localhost:5202/api/...`, so without the backend (or a matching CORS/proxy setup) the UI loads but shows empty-state surfaces with `net::ERR_FAILED`/CORS errors instead of real job data.
 - In this CRA frontend, `react-scripts` resolves the app directory from the current working directory. Run UI tests/builds from `job-tracker-ui/` (for example `cd job-tracker-ui && CI=true ./node_modules/.bin/react-scripts ...`) instead of invoking `npm --prefix job-tracker-ui ...` from the repo root, or `react-scripts` may fail looking for a root-level `package.json`.
+- The S06 acceptance seed must backdate both `JobApplication.FollowUpAt` and the latest correspondence timestamp past the user’s `AppliedFollowUpDays` threshold; `RulesEngine` computes `Waiting` follow-up from the most recent activity (`DateApplied`, `ResponseDate`, `FollowUpAt`, `FeedbackRequestedAt`, or last correspondence), so a recent reminder date can suppress the intended `workflowSignal.actionKey = "follow-up"` fixture.