feat(P03): multi-project support, NFR milestone versioning, phase context reset, install scripts (v0.3.0)

opencode/ci/references/git-context-loading.md

@@ -76,6 +76,34 @@ interface ParsedCiCommit {
 
 Commits without `---ci---` blocks have `ci: null` — these are treated as non-CI commits (e.g., manual edits by the developer).
 
+## Phase Context Reset
+
+Between phases, all state is committed to git, then the next phase starts with fresh context from git log — not accumulated conversation history.
+
+**On opencode (subagent support):** spawn a fresh agent for the next phase. The new agent loads context from git log and `.ci/` files only.
+
+**On platforms without subagents:** simulated reset — re-read git context from scratch, ignore prior conversation history. Treat the phase boundary as a hard context boundary.
+
+**Checkpoint sequence:**
+1. Commit all work from the current phase
+2. Update `.ci/` files (ROADMAP.md phase status, REQUIREMENTS.md requirement statuses)
+3. Verify `GitContext.reconstructState()` matches expected state
+4. Reset context — next phase begins fresh
+
+The phase context reset ensures that each phase operates on verified git state, preventing context drift across long-running projects.
+
+## Multi-Project Context
+
+GitContext supports multi-project mode with optional project scoping:
+
+| Method | Returns | Purpose |
+|--------|---------|---------|
+| `GitContext(projectPath, projectSlug?)` | GitContext | Optional project slug for scoping |
+| `detectProjectFromCommit()` | string \| null | Detect project from latest commit's `project` field |
+| `isNfrMilestone()` | boolean | Check if current milestone is NFR-only (no feat phases) |
+
+In multi-project mode, `detectProjectFromCommit()` reads the `project` field from the latest `---ci---` block to determine which project context to load. `isNfrMilestone()` inspects phase commit types to determine versioning behavior.
+
 ## Context Budget Strategy
 
 When context is limited: