Phase 1-3: Add memory, skills, and improvement systems

- memory/: cross-session project memory with decisions, lessons, failures,
  architecture, and sessions categories. Each has format templates and
  lifecycle documentation.
- skills/: 12 reusable specialized methodologies (tdd, systematic-debugging,
  architecture-design, code-review, security-review, repository-analysis,
  failure-analysis, refactoring, test-analysis, incident-investigation,
  browser-automation, research). Each has frontmatter and methodology sections.
- improvements/: proposal-based improvement system requiring human approval.
- scripts/memory-lifecycle.sh: deterministic memory operations (recall, store,
  list, search, sessions, cleanup).
- scripts/test-memory-system.sh: 12 structural tests for all new systems.
- orchestrator.md: added Memory Recall stage, Learning and Memory Storage
  stage, Improvement Proposals workflow, memory/skills rules, and 3 new
  actions (A23-A27) to the action catalog. Updated behavioral acceptance test
  and state separation model.
- All 12 subagents: added Memory & Skills Awareness sections with recall
  and store instructions.
- docs/AGENT_ARCHITECTURE.md: documented memory, skills, and improvements
  systems (sections 12-14). Updated action count (27), state model, and
  remaining weaknesses.
- README.md: documented new systems, updated repository layout, added
  test-memory-system.sh documentation.

All 39 tests pass (16 architecture + 12 memory + 11 bootstrap).

skills/test-analysis/SKILL.md

@@ -0,0 +1,59 @@
+---
+name: test-analysis
+description: Test analysis — evaluating test quality, coverage gaps, and test strategy
+version: "1.0"
+owner: Tester
+prerequisites: test suite exists
+---
+
+# Test Analysis
+
+## When to use this skill
+
+- Evaluating test quality before accepting changes
+- Identifying coverage gaps
+- Designing test strategy for new features
+
+## Core methodology
+
+```text
+EXAMINE TESTS → ASSESS COVERAGE → EVALUATE QUALITY → IDENTIFY GAPS → PRIORITIZE → RECOMMEND
+```
+
+## Analysis dimensions
+
+### Coverage
+- What code paths are exercised?
+- What branches are tested?
+- What error conditions are covered?
+
+### Quality
+- Do tests verify behavior (not implementation)?
+- Are tests independent (no ordering dependencies)?
+- Are tests deterministic (no flakiness)?
+- Are assertions meaningful (not just "no crash")?
+
+### Completeness
+- Are edge cases tested?
+- Are boundary conditions covered?
+- Are error paths tested?
+- Are integration points verified?
+
+### Maintainability
+- Are tests readable?
+- Are tests well-organized?
+- Are tests fast enough for the feedback loop?
+
+## Common pitfalls
+
+- Testing implementation details (breaks on refactor)
+- Writing tests that always pass (no real verification)
+- Missing the failure path (happy path only)
+- Slow tests that discourage running them
+- Flaky tests that erode confidence
+
+## Exit criteria
+
+- Coverage gaps identified with severity
+- Test quality assessment complete
+- Recommendations for improvement prioritized