Standardize skill metadata: remove -user suffixes and add missing frontmatter

- Renamed 4 skill directories to remove -user suffix (improve-codebase-architecture,
  prd-to-issues, prd-to-plan, write-a-prd)
- Added frontmatter (name + description) to 5 skills that were missing it
  (grill-me, prd-to-issues, scaffold-exercises, obsidian-vault, write-a-prd)
- Improved vague descriptions on edit-article and request-refactor-plan

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

improve-codebase-architecture/REFERENCE.md

@@ -0,0 +1,78 @@
+# Reference
+
+## Dependency Categories
+
+When assessing a candidate for deepening, classify its dependencies:
+
+### 1. In-process
+
+Pure computation, in-memory state, no I/O. Always deepenable — just merge the modules and test directly.
+
+### 2. Local-substitutable
+
+Dependencies that have local test stand-ins (e.g., PGLite for Postgres, in-memory filesystem). Deepenable if the test substitute exists. The deepened module is tested with the local stand-in running in the test suite.
+
+### 3. Remote but owned (Ports & Adapters)
+
+Your own services across a network boundary (microservices, internal APIs). Define a port (interface) at the module boundary. The deep module owns the logic; the transport is injected. Tests use an in-memory adapter. Production uses the real HTTP/gRPC/queue adapter.
+
+Recommendation shape: "Define a shared interface (port), implement an HTTP adapter for production and an in-memory adapter for testing, so the logic can be tested as one deep module even though it's deployed across a network boundary."
+
+### 4. True external (Mock)
+
+Third-party services (Stripe, Twilio, etc.) you don't control. Mock at the boundary. The deepened module takes the external dependency as an injected port, and tests provide a mock implementation.
+
+## Testing Strategy
+
+The core principle: **replace, don't layer.**
+
+- Old unit tests on shallow modules are waste once boundary tests exist — delete them
+- Write new tests at the deepened module's interface boundary
+- Tests assert on observable outcomes through the public interface, not internal state
+- Tests should survive internal refactors — they describe behavior, not implementation
+
+## Issue Template
+
+<issue-template>
+
+## Problem
+
+Describe the architectural friction:
+
+- Which modules are shallow and tightly coupled
+- What integration risk exists in the seams between them
+- Why this makes the codebase harder to navigate and maintain
+
+## Proposed Interface
+
+The chosen interface design:
+
+- Interface signature (types, methods, params)
+- Usage example showing how callers use it
+- What complexity it hides internally
+
+## Dependency Strategy
+
+Which category applies and how dependencies are handled:
+
+- **In-process**: merged directly
+- **Local-substitutable**: tested with [specific stand-in]
+- **Ports & adapters**: port definition, production adapter, test adapter
+- **Mock**: mock boundary for external services
+
+## Testing Strategy
+
+- **New boundary tests to write**: describe the behaviors to verify at the interface
+- **Old tests to delete**: list the shallow module tests that become redundant
+- **Test environment needs**: any local stand-ins or adapters required
+
+## Implementation Recommendations
+
+Durable architectural guidance that is NOT coupled to current file paths:
+
+- What the module should own (responsibilities)
+- What it should hide (implementation details)
+- What it should expose (the interface contract)
+- How callers should migrate to the new interface
+
+</issue-template>