ui: CWD for agent (#26518)

* server : extend file_glob_search for UI pickers

* ui : add per-conversation working directory with picker

* ui : add path navigation and search scope to cwd picker

Treat path-like queries (starting with / or ~) as directory navigation
instead of glob-matching the whole query: search the parent for the last
segment, and descend into an exactly-typed directory by listing its
children. Show the effective search scope in the footer and auto-search
on open so the current directory and its siblings appear immediately.

Assisted-by: Claude

* db : persist per-call tool cwd on tool result messages

* ui : abbreviate tool paths under home with a tilde

* ui : show the per-call cwd on exec shell rows

* ui : clarify the synthetic cwd message for the model

* ui : reuse the trailing cwd row on a repeated pick

* ui : don't jump when a cwd row is injected mid-chat

* chore: Formatting

* refactor: Cleanup comments

* ui : unify working directory naming and add a synthetic-message flag

* ui : render synthetic cwd rows without a scroll jump

* ui : decouple the working directory picker into utils and sub-components

* ui : add get_info tool call block

* chore: Formatting

* refactor: Cleanup

* refactor: Cleanup

* refactor: Cleanup

* fix: UI

* server : harden file_glob_search listing (kind enum, timeout, symlink guard, absolute base)

* ui : use persisted isSynthetic flag for cwd rows, drop legacy formats

* ui : cache picker search, fail visibly on native resolve

* ui : escape glob metacharacters in picker search glob

* ui : simplify auto-scroll pin

* chore: Format

* fix: Use `SvelteMap`

* refactor: Post-review fixes

* ui: accept Windows roots in the working directory picker

recognize a drive root (C:) and a UNC share (//host/share) as path
navigation, alongside the POSIX root and ~, so a query like D:\repos
lists that directory instead of glob-matching it under the home dir

split below the root, so a bare drive resolves to its root rather than
to a drive-relative prefix

rewrite backslashes into forward slashes only when the query carries a
Windows root, since a backslash is a legal POSIX filename character

paths keep travelling with forward slashes, which is what the server
returns and what Windows accepts

---------

Co-authored-by: Pascal <admin@serveurperso.com>

tools/ui/tests/unit/tool-calls.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, it } from 'vitest';
 import { AgenticSectionType, BuiltInTool } from '$lib/enums';
 import type { AgenticSection } from '$lib/utils';
 import { parseToolArgs } from '$lib/components/app/chat/ChatMessages/ChatMessage/ChatMessageToolCall/parsers/_shared';
+import { lastPathSegment, abbreviateHome, formatCwdMessage, parseCwdMessage } from '$lib/utils';
 import {
 	parseWriteFileMeta,
 	type WriteFileMeta
@@ -27,6 +28,90 @@ function makeSection(
 	};
 }
 
+describe('lastPathSegment', () => {
+	it('returns the last segment of an absolute path', () => {
+		expect(lastPathSegment('/Users/me/code/my-project')).toBe('my-project');
+	});
+
+	it('returns the last segment of a tilde-relative path', () => {
+		expect(lastPathSegment('~/git/llama.brand')).toBe('llama.brand');
+	});
+
+	it('strips trailing slashes', () => {
+		expect(lastPathSegment('/foo/bar/')).toBe('bar');
+	});
+
+	it('strips multiple trailing slashes', () => {
+		expect(lastPathSegment('/foo/bar///')).toBe('bar');
+	});
+
+	it('returns the input unchanged when there is no slash', () => {
+		expect(lastPathSegment('project')).toBe('project');
+	});
+
+	it('returns tilde when only tilde is given', () => {
+		expect(lastPathSegment('~/')).toBe('~');
+	});
+});
+
+describe('abbreviateHome', () => {
+	it('abbreviates paths under home with a tilde', () => {
+		expect(abbreviateHome('/Users/al/Documents/x.txt', '/Users/al')).toBe('~/Documents/x.txt');
+	});
+
+	it('abbreviates home itself to a bare tilde', () => {
+		expect(abbreviateHome('/Users/al', '/Users/al')).toBe('~');
+	});
+
+	it('returns paths outside home unchanged', () => {
+		expect(abbreviateHome('/opt/project', '/Users/al')).toBe('/opt/project');
+	});
+
+	it('does not abbreviate a mere prefix match', () => {
+		expect(abbreviateHome('/Users/alice/x', '/Users/al')).toBe('/Users/alice/x');
+	});
+
+	it('returns the path unchanged when home is unknown', () => {
+		expect(abbreviateHome('/Users/al/Documents', null)).toBe('/Users/al/Documents');
+	});
+});
+
+describe('formatCwdMessage / parseCwdMessage', () => {
+	it('formats a cwd change matching the UI text, with a file link', () => {
+		expect(formatCwdMessage('/Users/al/Documents', '/Users/al')).toBe(
+			'Set working directory to [file:///Users/al/Documents](~/Documents).'
+		);
+	});
+
+	it('falls back to the basename display when home is unknown', () => {
+		expect(formatCwdMessage('/opt/project', null)).toBe(
+			'Set working directory to [file:///opt/project](project).'
+		);
+	});
+
+	it('round-trips through the parser', () => {
+		const info = parseCwdMessage(formatCwdMessage('/Users/al/Documents', '/Users/al'));
+		expect(info?.path).toBe('/Users/al/Documents');
+		expect(info?.display).toBe('~/Documents');
+	});
+
+	it('parses a cwd message even when guidance follows the link', () => {
+		expect(
+			parseCwdMessage(
+				'Set working directory to [file:///a/b](~/b). Tool calls run with this as their working directory.'
+			)
+		).toEqual({ path: '/a/b', display: '~/b' });
+	});
+
+	it('parses the cleared marker', () => {
+		expect(parseCwdMessage('Working directory cleared')).toEqual({ path: null, display: '' });
+	});
+
+	it('returns null for non-cwd content', () => {
+		expect(parseCwdMessage('hello there')).toBeNull();
+	});
+});
+
 describe('parseToolArgs (shared)', () => {
 	it('returns null when the section has no toolArgs', () => {
 		const result = parseToolArgs(BuiltInTool.READ_FILE, makeSection({ toolArgs: undefined }));