Update constructor calls (6-arg), seed AppSettings with sibling strategy,
git-init working dirs via GitRepoFixture.InitRepoWithInitialCommit, and
replace McpConfigPath assertions with worktree-path / .mcp.json checks.
Also fixes PlanningHubTests which had the same 3-arg constructor.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Add PlanningSessionFiles, PlanningSessionStartContext/ResumeContext DTOs,
PlanningSessionManager.StartAsync (file scaffolding + status transition),
and integration tests. Also fix migration discovery by adding [DbContext]
attribute to all migration classes and switch DbFixture to EnsureCreated.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
