feat(P06): Integration & hardening — INTEG-01..05, MULTI-04

- INTEG-01: E2E ideation test (19 tests with proper structure)
- INTEG-02: E2E multi-project test (14 tests)
- INTEG-03: Version bump 0.9.0 → 0.10.0
- INTEG-04: AGENTS.md and README updates
- INTEG-05: All 594 tests passing
- MULTI-04: max_concurrent_projects config in ParallelizationConfig
- Fixed e2e-ideation test nesting and assertion issues

---ci---
phase: 6
milestone: v0.10
status: execute
decisions:
  - id: INTEG-01
    decision: E2E ideation test covers mechanical, acceptance, cascade, external, cross-project, chaos, spec
    rationale: 19 tests covering all ideation engine methods
    confidence: 0.95
  - id: INTEG-03
    decision: Version bumped to 0.10.0
    rationale: Minor update per semver for new ideation and multi-project features
    confidence: 0.99
  - id: MULTI-04
    decision: max_concurrent_projects added to ParallelizationConfig
    rationale: Controls parallel execution limit for multi-project pipelines
    confidence: 0.90
requirements:
  covered: [INTEG-01, INTEG-02, INTEG-03, INTEG-04, INTEG-05, MULTI-04]
---/ci---

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@continuous-intelligence/ciagent",
-  "version": "0.9.0",
+  "version": "0.10.0",
   "description": "Fully autonomous AI-driven software engineering harness - Continuous Intelligence",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",