Improve agent autonomy and diff view readability

Agent behavior improvements:
  - Add project context detection (tsconfig.json, pom.xml, etc.)
  - Enforce validation after changes (tsc --noEmit, mvn compile, etc.)
  - Run tests automatically - never ask "do you want me to run tests"
  - Complete full loop: create → type-check → test → confirm
  - Add command detection for direct execution (run tree, run ls)

  Diff view improvements:
  - Use darker backgrounds for added/removed lines
  - Add diffLineBgAdded, diffLineBgRemoved, diffLineText theme colors
  - Improve text visibility with white text on dark backgrounds
  - Update both React/Ink and SolidJS diff components

  Streaming fixes:
  - Fix tool call argument accumulation using OpenAI index field
  - Fix streaming content display after tool calls
  - Add consecutive error tracking to prevent token waste

  Other changes:
  - ESC to abort operations, Ctrl+C to exit
  - Fix model selection when provider changes in cascade mode
  - Add debug logging for troubleshooting
  - Move tests to root tests/ folder
  - Fix banner test GRADIENT_COLORS reference

tsconfig.json

@@ -11,6 +11,7 @@
     "baseUrl": ".",
     "paths": {
       "@/*": ["src/*"],
+      "@api/*": ["src/api/*"],
       "@commands/*": ["src/commands/*"],
       "@constants/*": ["src/constants/*"],
       "@interfaces/*": ["src/interfaces/*"],