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/repository-analysis/SKILL.md

@@ -0,0 +1,68 @@
+---
+name: repository-analysis
+description: Systematic repository exploration — understanding codebase structure, patterns, and conventions
+version: "1.0"
+owner: Explorer
+prerequisites: repo access
+---
+
+# Repository Analysis
+
+## When to use this skill
+
+- First encounter with a repository
+- Understanding a new area of a familiar repository
+- Before architectural or implementation decisions
+
+## Step-by-step procedure
+
+### 1. Orientation
+- Read README, package.json/pyproject.toml, or equivalent
+- Identify the project's purpose, language, and framework
+- Note the top-level structure
+
+### 2. Entry points
+- Find the main entry points (main, index, app)
+- Trace the execution flow from entry to key functionality
+- Identify the public API surface
+
+### 3. Structure
+- Map the directory structure to logical components
+- Identify module boundaries and dependencies
+- Note naming conventions
+
+### 4. Build & test
+- Identify the build system and commands
+- Find the test suite and how to run it
+- Check for linting, type-checking, CI configuration
+
+### 5. Conventions
+- Note coding style (formatting, naming, patterns)
+- Identify architectural patterns (MVC, layered, etc.)
+- Check for existing documentation of conventions
+
+### 6. Dependencies
+- Review external dependencies
+- Note version constraints and lock files
+- Identify any custom or vendored dependencies
+
+## Common pitfalls
+
+- Exploring too broadly (lost in the codebase)
+- Not recording findings (have to re-explore)
+- Confusing what exists with what is intended
+- Not distinguishing generated from hand-written code
+- Ignoring test files (they reveal intent)
+
+## Evidence requirements
+
+- File:line references for key findings
+- Confidence levels for uncertain findings
+- Questions for follow-up investigation
+
+## Exit criteria
+
+- System map with key files and their roles
+- Confidence levels for each finding
+- Open questions listed
+- Findings recorded in report