feat: enhance test-task-generate with Gemini enrichment and planning-notes mechanism

Implement two major enhancements to test generation workflow:

1. Gemini Test Enhancement (Phase 1.5)
   - Add Gemini CLI analysis for comprehensive test suggestions
   - Generate enriched test specifications for L1-L3 test layers
   - Focus on API contracts, integration patterns, error scenarios
   - Create gemini-enriched-suggestions.md as artifact

2. Planning Notes Mechanism (test-planning-notes.md)
   - Similar to plan.md's planning-notes pattern
   - Record Test Intent (Phase 1)
   - Embed complete Gemini enrichment (Phase 1.5)
   - Track consolidated test requirements
   - Support N+1 context with decisions and deferred items

Implementation Details:
   - Created Gemini prompt template: test-suggestions-enhancement.txt
   - Enhanced test-task-generate.md with Phase 1, 1.5, 2 logic
   - Gemini content embedded in planning-notes for single source of truth
   - test-action-planning-agent reads both TEST_ANALYSIS_RESULTS.md and test-planning-notes.md
   - Backward compatible: Phase 1.5 is optional enhancement

Benefits:
   - Comprehensive test coverage (API, integration, error scenarios)
   - Full traceability of test planning process
   - Consolidated context in one file for easy review
   - Preserved Gemini output as independent artifact

.claude/workflows/cli-templates/prompts/test/test-suggestions-enhancement.txt

@@ -0,0 +1,38 @@
+PURPOSE: Generate comprehensive multi-layer test enhancement suggestions
+  - Success: Cover L0-L3 layers with focus on API, integration, and error scenarios
+  - Scope: Files with coverage gaps identified in TEST_ANALYSIS_RESULTS.md
+  - Goal: Provide specific, actionable test case suggestions that increase coverage completeness
+
+TASK:
+  • L1 (Unit Tests): Suggest edge cases, boundary conditions, error paths, state transitions
+  • L2.1 (Integration): Suggest module interaction patterns, dependency injection scenarios
+  • L2.2 (API Contracts): Suggest request/response test cases, validation, status codes, error responses
+  • L2.4 (External APIs): Suggest mock strategies, failure scenarios, timeout handling, retry logic
+  • L2.5 (Failure Modes): Suggest exception hierarchies, error propagation, recovery strategies
+  • Cross-cutting: Suggest performance test cases, security considerations
+
+MODE: analysis
+
+CONTEXT: @.workflow/active/{test-session-id}/.process/TEST_ANALYSIS_RESULTS.md
+  Memory: Project type, test framework, existing test patterns, coverage gaps
+
+EXPECTED: Markdown report with structured test enhancement suggestions organized by:
+  1. File-level test requirements (per file needing tests)
+  2. Layer-specific test cases (L1, L2.1, L2.2, L2.4, L2.5)
+  3. Each suggestion includes:
+     - Test type and layer (e.g., "L2.2 API Contract Test")
+     - Specific test case description (e.g., "POST /api/users - Invalid email format")
+     - Expected behavior (e.g., "Returns 400 with validation error message")
+     - Dependencies/mocks needed (e.g., "Mock email service")
+     - Success criteria (e.g., "Status 400, error.field === 'email'")
+  4. Test ordering/dependencies (which tests should run first)
+  5. Integration test strategies (how components interact)
+  6. Error scenario matrix (all failure modes covered)
+
+CONSTRAINTS:
+  - Focus on identified coverage gaps from TEST_ANALYSIS_RESULTS.md
+  - Prioritize API tests, integration tests, and error scenarios
+  - No code generation - suggestions only with sufficient detail for implementation
+  - Consider project conventions and existing test patterns
+  - Each suggestion should be actionable and specific (not generic)
+  - Output format: Markdown with clear section headers