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/architecture-constraints.md

@@ -0,0 +1,32 @@
+---
+title: "Architecture Constraints"
+dimension: specs
+category: planning
+keywords:
+  - architecture
+  - module
+  - layer
+  - pattern
+readMode: required
+priority: high
+---
+
+# Architecture Constraints
+
+## Module Boundaries
+
+- Each module owns its data and exposes a public API
+- No circular dependencies between modules
+- Shared utilities live in a dedicated shared layer
+
+## Layer Separation
+
+- Presentation layer must not import data layer directly
+- Business logic must be independent of framework specifics
+- Configuration must be externalized, not hardcoded
+
+## Dependency Rules
+
+- External dependencies require justification
+- Prefer standard library when available
+- Pin dependency versions for reproducibility