feat: add injection preview functionality and enhance specs management

- Implemented injection preview feature in InjectionControlTab with file listing and content preview.
- Added new API endpoint for fetching injection preview data.
- Introduced content length caching for performance optimization.
- Enhanced spec loading to support category filtering.
- Updated localization files for new features and terms.
- Created new personal and project specs for coding style and architecture constraints.
- Improved CLI options for category selection in spec commands.

.ccw/specs/coding-conventions.md

@@ -0,0 +1,38 @@
+---
+title: "Coding Conventions"
+dimension: specs
+category: general
+keywords:
+  - typescript
+  - naming
+  - style
+  - convention
+readMode: required
+priority: high
+---
+
+# Coding Conventions
+
+## Naming
+
+- Use camelCase for variables and functions
+- Use PascalCase for classes and interfaces
+- Use UPPER_SNAKE_CASE for constants
+
+## Formatting
+
+- 2-space indentation
+- Single quotes for strings
+- Trailing commas in multi-line constructs
+
+## Patterns
+
+- Prefer composition over inheritance
+- Use early returns to reduce nesting
+- Keep functions under 30 lines when practical
+
+## Error Handling
+
+- Always handle errors explicitly
+- Prefer typed errors over generic catch-all
+- Log errors with sufficient context