refactor: rename files to PascalCase components and kebab-case APIs (Task 4.4)

- Rename all component files to PascalCase matching exported names
- Move components into feature directories (git/, session/, project/, terminal/, workspace/, ui/, layout/)
- Rename all page files to PascalCase with Page suffix
- Rename all API files to kebab-case
- Update all imports across codebase with corrected relative depths
- Preserve git history via git mv

Quality gates: tsc (pass), eslint (pass), 66/74 tests pass (8 pre-existing failures)
Refs: repo-restructure Task 4.4

apps/web/src/api/config-folders.test.ts

@@ -5,7 +5,7 @@ import {
   deleteConfigFolder,
   listConfigFolders,
   updateConfigFolder,
-} from "../api/config_folders";
+} from "../api/config-folders";
 
 const mockGet = vi.fn();
 const mockPost = vi.fn();

apps/web/src/api/tool-types.test.ts

@@ -6,7 +6,7 @@ import {
   listToolTypes,
   updateToolType,
   validateToolType,
-} from "../api/tool_types";
+} from "../api/tool-types";
 
 const mockGet = vi.fn();
 const mockPost = vi.fn();