fix(P01): quick wins — remove dead refs, unused imports, fix postinstall, version bump

---ci---
project: ci
phase: 1
milestone: v0.5
status: complete
decisions:
  - id: D-020
    decision: Phase 1 Quick Wins complete
    rationale: All 5 FIX requirements (FIX-01 through FIX-05) verified and passing
    confidence: 0.95
    alternatives: []
requirements:
  covered: [FIX-01, FIX-02, FIX-03, FIX-04, FIX-05]
---/ci---

Phase 1 (Quick Wins) summary:
- A1/FIX-01: Marked .planning/ refs as (legacy)/(removed) in docs
- A2/FIX-02: Removed unused execSync import from ollama-base.ts
- A3/FIX-03: Replaced postinstall with explicit install-opencode, removed scripts/ from files
- A4/FIX-04: Verified opencode.json is clean (no learnship entry)
- A5/FIX-05: Version bump to 0.5.0

opencode/ci/VERSION

@@ -1 +1 @@
-0.4.0
+0.5.0

opencode/ci/references/ci-files-discipline.md

@@ -41,7 +41,7 @@ These were removed in v0.2.0 and now live in the git log:
 | `.ci/audit/decisions.json` | `---ci---` decisions block | `GitContext.getDecisions()` |
 | `.ci/audit/escalations.json` | `---ci---` escalations block | `GitContext.getEscalations()` |
 | `.ci/audit/lessons.json` | `---ci---` lessons block | `GitContext.getLessons()` |
-| `.planning/` directory | Git log + branches | `GitContext.reconstructState()` |
+| `.planning/` directory (removed) | Git log + branches | `GitContext.reconstructState()` |
 
 ## CiFiles API