feat(coding-agent/tools)!: replaced paths arrays with path strings

- Replaced `grep`, `glob`, and `ast_grep` `paths` inputs with optional single `path` strings while preserving default workspace-root behavior.
- Added shared `toPathList` normalization for legacy arrays and JSON-encoded arrays across tool execution and TUI renderers.
- Updated prompts, fixtures, shims, transcript summaries, and tests to send and display the new `path` argument.
- Updated collab-web search tool cards to read `path` while falling back to legacy `paths` for historical transcripts.
- Recorded the contiguous coding-agent changelog run for the tool-path breaking change and adjacent TTS entries.

packages/coding-agent/src/cli/gallery-fixtures/fs.ts

@@ -182,8 +182,8 @@ export const fsFixtures: Record<string, GalleryFixture> = {
 	glob: {
 		label: "Glob",
 		// Streaming: glob half-typed, no limit yet.
-		streamingArgs: { paths: ["packages/coding-agent/src/tools/*-render"] },
-		args: { paths: ["packages/coding-agent/src/**/*.test.ts"], limit: 50 },
+		streamingArgs: { path: "packages/coding-agent/src/tools/*-render" },
+		args: { path: "packages/coding-agent/src/**/*.test.ts", limit: 50 },
 		result: {
 			content: [
 				{

packages/coding-agent/src/cli/gallery-fixtures/search.ts

@@ -9,7 +9,7 @@ export const searchFixtures: Record<string, GalleryFixture> = {
 		},
 		args: {
 			pattern: "useState",
-			paths: ["packages/tui/src"],
+			path: "packages/tui/src",
 		},
 		result: {
 			content: [
@@ -160,7 +160,7 @@ export const searchFixtures: Record<string, GalleryFixture> = {
 		},
 		args: {
 			pat: "useState($A)",
-			paths: ["packages/tui/src/components"],
+			path: "packages/tui/src/components",
 		},
 		result: {
 			content: [