refactor(coding-agent)!: removed StringEnum helper and shortened tool schema descriptions

- Replaced all StringEnum(...) usages with z.enum([...]) across tools, examples, and tests.
- Removed StringEnum re-export from @oh-my-pi/pi-coding-agent public API.
- Condensed verbose tool parameter descriptions to minimal lowercase phrases.
- Renamed AuthCredentialStore to SqliteAuthCredentialStore at usage sites.

packages/coding-agent/src/commit/agentic/tools/analyze-file.ts

@@ -13,8 +13,8 @@ import type { ToolSession } from "../../../tools";
 import { getFilePriority } from "./git-file-diff";
 
 const analyzeFileSchema = z.object({
-	files: z.array(z.string().describe("File path")).min(1),
-	goal: z.string().describe("Optional analysis focus").optional(),
+	files: z.array(z.string().describe("file path")).min(1),
+	goal: z.string().describe("analysis focus").optional(),
 });
 
 const analyzeFileOutputSchema = {

packages/coding-agent/src/commit/agentic/tools/git-file-diff.ts

@@ -132,8 +132,8 @@ function processDiffs(files: string[], diffs: Map<string, string>): { result: st
 }
 
 const gitFileDiffSchema = z.object({
-	files: z.array(z.string().describe("Files to diff")).min(1).max(10),
-	staged: z.boolean().describe("Use staged changes (default: true)").optional(),
+	files: z.array(z.string().describe("file to diff")).min(1).max(10),
+	staged: z.boolean().describe("use staged changes (default true)").optional(),
 });
 
 export function createGitFileDiffTool(cwd: string, state: CommitAgentState): CustomTool<typeof gitFileDiffSchema> {

packages/coding-agent/src/commit/agentic/tools/git-hunk.ts

@@ -4,9 +4,9 @@ import type { CustomTool } from "../../../extensibility/custom-tools/types";
 import * as git from "../../../utils/git";
 
 const gitHunkSchema = z.object({
-	file: z.string().describe("File path"),
-	hunks: z.array(z.number().describe("1-based hunk indices")).min(1).optional(),
-	staged: z.boolean().describe("Use staged changes (default: true)").optional(),
+	file: z.string().describe("file path"),
+	hunks: z.array(z.number().describe("1-based hunk index")).min(1).optional(),
+	staged: z.boolean().describe("use staged changes (default true)").optional(),
 });
 
 function selectHunks(fileHunks: FileHunks, requested?: number[]): DiffHunk[] {

packages/coding-agent/src/commit/agentic/tools/git-overview.ts

@@ -43,8 +43,8 @@ function filterExcludedFiles(files: string[]): { filtered: string[]; excluded: s
 }
 
 const gitOverviewSchema = z.object({
-	staged: z.boolean().describe("Use staged changes (default: true)").optional(),
-	include_untracked: z.boolean().describe("Include untracked files when staged=false").optional(),
+	staged: z.boolean().describe("use staged changes (default true)").optional(),
+	include_untracked: z.boolean().describe("include untracked when unstaged").optional(),
 });
 
 export function createGitOverviewTool(cwd: string, state: CommitAgentState): CustomTool<typeof gitOverviewSchema> {

packages/coding-agent/src/commit/agentic/tools/propose-changelog.ts

@@ -12,9 +12,7 @@ const changelogEntryProperties = CHANGELOG_CATEGORIES.reduce<Record<ChangelogCat
 );
 
 const changelogEntriesSchema = z.object(changelogEntryProperties);
-const changelogDeletionsSchema = z
-	.object(changelogEntryProperties)
-	.describe("Entries to remove from existing changelog sections (case-insensitive match)");
+const changelogDeletionsSchema = z.object(changelogEntryProperties).describe("entries to remove");
 
 const changelogEntrySchema = z.object({
 	path: z.string(),

packages/coding-agent/src/commit/agentic/tools/recent-commits.ts

@@ -3,7 +3,7 @@ import type { CustomTool } from "../../../extensibility/custom-tools/types";
 import * as git from "../../../utils/git";
 
 const recentCommitsSchema = z.object({
-	count: z.number().min(1).max(50).describe("Number of commits to fetch").optional(),
+	count: z.number().min(1).max(50).describe("commit count").optional(),
 });
 
 interface RecentCommitStats {

packages/coding-agent/src/commit/agentic/tools/schemas.ts

@@ -17,15 +17,7 @@ export const commitTypeSchema = z.enum([
 export const detailSchema = z.object({
 	text: z.string(),
 	changelog_category: z
-		.union([
-			z.literal("Added"),
-			z.literal("Changed"),
-			z.literal("Fixed"),
-			z.literal("Deprecated"),
-			z.literal("Removed"),
-			z.literal("Security"),
-			z.literal("Breaking Changes"),
-		])
+		.enum(["Added", "Changed", "Fixed", "Deprecated", "Removed", "Security", "Breaking Changes"])
 		.optional(),
 	user_visible: z.boolean().optional(),
 });