diff --git a/lib/builtin/claude/src/conversation_view.dart b/lib/builtin/claude/src/conversation_view.dart
index 14e1161d..b4989c3c 100644
--- a/lib/builtin/claude/src/conversation_view.dart
+++ b/lib/builtin/claude/src/conversation_view.dart
@@ -392,12 +392,19 @@ void _openUrl(BuildContext context, String url) {
 }
 
 /// Resolve a path-like token from the conversation to an absolute workspace
-/// file, or null if it doesn't name a real repo file (T-300). The existence
-/// check is what keeps prose ("e.g.", "2.2.0") from linkifying. Resolves
-/// relative tokens against the open project root; absolute tokens must already
-/// live inside it. `..` segments are rejected so a ref can't escape the repo.
-String? _resolveRepoFile(BuildContext context, String raw) {
-  final root = ClideKernel.of(context).project.current?.path;
+/// file, or null if it doesn't name a real repo file (T-300). Delegates the
+/// (pure, testable) path logic to [resolveWorkspaceFilePath] with the open
+/// project root.
+String? _resolveRepoFile(BuildContext context, String raw) =>
+    resolveWorkspaceFilePath(ClideKernel.of(context).project.current?.path, raw);
+
+/// Resolve [raw] (a path-like token) against the workspace [root] to an absolute
+/// path, or null if it doesn't name a real file under the repo (T-300). The
+/// existence check is what keeps prose ("e.g.", "2.2.0") from linkifying.
+/// Relative tokens resolve against [root]; absolute tokens must already live
+/// inside it. `..` segments are rejected so a ref can't escape the repo.
+@visibleForTesting
+String? resolveWorkspaceFilePath(String? root, String raw) {
   if (root == null || raw.isEmpty || raw.contains('..')) return null;
   final abs = raw.startsWith('/') ? raw : '$root/$raw';
   if (!abs.startsWith('$root/')) return null;
diff --git a/lib/builtin/claude/src/extension.dart b/lib/builtin/claude/src/extension.dart
index 4a5b7dd3..b6ca7724 100644
--- a/lib/builtin/claude/src/extension.dart
+++ b/lib/builtin/claude/src/extension.dart
@@ -11,6 +11,7 @@ import 'package:clide/builtin/claude/src/pane_context_status.dart';
 import 'package:clide/builtin/claude/src/claude_meta_sidebar.dart';
 import 'package:clide/builtin/claude/src/session_index.dart';
 import 'package:clide/builtin/claude/src/session_storage.dart';
+import 'package:clide/builtin/claude/src/ticket_pick_up.dart';
 import 'package:clide/builtin/claude/src/transcript_reader.dart' show ImageMessage;
 import 'package:clide/src/daemon/image_commands.dart' show imageShowChannel;
 import 'package:clide/builtin/claude/src/team_chat_sidebar.dart' show TeamChatPane;
@@ -471,41 +472,3 @@ class ClaudeExtension extends ClideExtension {
     return IpcResponse.ok(id: '', data: const {'status': 'shown'});
   }
 }
-
-/// Statuses a pick-up may advance from: a not-yet-started ticket. Picking up a
-/// ticket that's already `in_progress`/`review`/`done`/`cancelled` injects the
-/// prompt but leaves the status alone, so a re-pick-up never drags it backwards
-/// or reopens it (T-339).
-const _kPickUpStartableStatuses = {'backlog', 'ready'};
-
-/// Inject a picked-up ticket's prompt into the active session (the `primary`
-/// lead, else the first visible one) and, on acceptance from a not-yet-started
-/// ticket, advance it to `in_progress` and publish a `changed` so the sidebar
-/// refreshes (T-327/T-339). Returns whether a live session accepted the prompt.
-///
-/// With no live session there's no injection and no state change — a quiet
-/// no-op. Kept free of the extension lifecycle so it's directly testable.
-@visibleForTesting
-Future<bool> applyTicketPickUp(
-  Map<String, Object?> data, {
-  required ClaudeSessionOrchestrator? orchestrator,
-  required DaemonClient ipc,
-  required MessageBus messages,
-}) async {
-  final prompt = data['prompt'] as String?;
-  if (prompt == null || prompt.isEmpty) return false;
-  final target = orchestrator?.byId('primary') ?? orchestrator?.visibleSessions.firstOrNull;
-  if (target == null) return false; // no live session → quiet no-op, no state change
-  orchestrator!.injectMessage(target.id, prompt);
-
-  final id = data['id'] as String?;
-  final status = data['status'] as String?;
-  if (id != null && id.isNotEmpty && _kPickUpStartableStatuses.contains(status)) {
-    final resp = await ipc.request('pql.tickets.status', args: {
-      'ids': [id],
-      'status': 'in_progress',
-    });
-    if (resp.ok) messages.publish('builtin.tickets', 'changed', {'id': id});
-  }
-  return true;
-}
diff --git a/lib/builtin/claude/src/ticket_pick_up.dart b/lib/builtin/claude/src/ticket_pick_up.dart
new file mode 100644
index 00000000..b3c6e7a7
--- /dev/null
+++ b/lib/builtin/claude/src/ticket_pick_up.dart
@@ -0,0 +1,46 @@
+/// Sidebar "pick up" handling (T-327/T-339): inject a ticket's prompt into the
+/// active Claude session and, on acceptance, advance the ticket to in_progress.
+///
+/// Kept out of `extension.dart` so it's unit-testable without dragging the whole
+/// (UI-wiring) extension into instrumentation.
+library;
+
+import 'package:clide/builtin/claude/src/session_orchestrator.dart';
+import 'package:clide/kernel/kernel.dart';
+
+/// Statuses a pick-up may advance from: a not-yet-started ticket. Picking up a
+/// ticket that's already `in_progress`/`review`/`done`/`cancelled` injects the
+/// prompt but leaves the status alone, so a re-pick-up never drags it backwards
+/// or reopens it (T-339).
+const kPickUpStartableStatuses = {'backlog', 'ready'};
+
+/// Inject a picked-up ticket's prompt into the active session (the `primary`
+/// lead, else the first visible one) and, on acceptance from a not-yet-started
+/// ticket, advance it to `in_progress` and publish a `changed` so the sidebar
+/// refreshes (T-327/T-339). Returns whether a live session accepted the prompt.
+///
+/// With no live session there's no injection and no state change — a quiet
+/// no-op.
+Future<bool> applyTicketPickUp(
+  Map<String, Object?> data, {
+  required ClaudeSessionOrchestrator? orchestrator,
+  required DaemonClient ipc,
+  required MessageBus messages,
+}) async {
+  final prompt = data['prompt'] as String?;
+  if (prompt == null || prompt.isEmpty) return false;
+  final target = orchestrator?.byId('primary') ?? orchestrator?.visibleSessions.firstOrNull;
+  if (target == null) return false; // no live session → quiet no-op, no state change
+  orchestrator!.injectMessage(target.id, prompt);
+
+  final id = data['id'] as String?;
+  final status = data['status'] as String?;
+  if (id != null && id.isNotEmpty && kPickUpStartableStatuses.contains(status)) {
+    final resp = await ipc.request('pql.tickets.status', args: {
+      'ids': [id],
+      'status': 'in_progress',
+    });
+    if (resp.ok) messages.publish('builtin.tickets', 'changed', {'id': id});
+  }
+  return true;
+}
diff --git a/test/builtin/claude/conversation_links_test.dart b/test/builtin/claude/conversation_links_test.dart
new file mode 100644
index 00000000..19b5764a
--- /dev/null
+++ b/test/builtin/claude/conversation_links_test.dart
@@ -0,0 +1,55 @@
+/// Tests for the workspace file-path resolver behind clickable conversation
+/// references (T-300): only real files under the repo root resolve; relative
+/// tokens resolve against the root, absolute tokens must already live inside it,
+/// and `..` escapes are rejected.
+library;
+
+import 'dart:io';
+
+import 'package:clide/builtin/claude/src/conversation_view.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  late Directory root;
+
+  setUp(() async {
+    root = await Directory.systemTemp.createTemp('clide_wsfile_');
+    await File('${root.path}/lib/app.dart').create(recursive: true);
+  });
+
+  tearDown(() async {
+    if (await root.exists()) await root.delete(recursive: true);
+  });
+
+  test('a relative path that exists resolves to its absolute path', () {
+    expect(resolveWorkspaceFilePath(root.path, 'lib/app.dart'), '${root.path}/lib/app.dart');
+  });
+
+  test('an absolute path inside the root resolves', () {
+    expect(resolveWorkspaceFilePath(root.path, '${root.path}/lib/app.dart'), '${root.path}/lib/app.dart');
+  });
+
+  test('a nonexistent path is null', () {
+    expect(resolveWorkspaceFilePath(root.path, 'lib/ghost.dart'), isNull);
+  });
+
+  test('a directory is not a file', () {
+    expect(resolveWorkspaceFilePath(root.path, 'lib'), isNull);
+  });
+
+  test('an absolute path outside the root is rejected', () {
+    expect(resolveWorkspaceFilePath(root.path, '/etc/passwd'), isNull);
+  });
+
+  test('a `..` escape is rejected', () {
+    expect(resolveWorkspaceFilePath(root.path, '../escape.dart'), isNull);
+  });
+
+  test('a null root (no project open) is null', () {
+    expect(resolveWorkspaceFilePath(null, 'lib/app.dart'), isNull);
+  });
+
+  test('an empty token is null', () {
+    expect(resolveWorkspaceFilePath(root.path, ''), isNull);
+  });
+}
diff --git a/test/builtin/claude/ticket_pick_up_test.dart b/test/builtin/claude/ticket_pick_up_test.dart
index d00cb680..88d7e794 100644
--- a/test/builtin/claude/ticket_pick_up_test.dart
+++ b/test/builtin/claude/ticket_pick_up_test.dart
@@ -5,9 +5,9 @@ library;
 
 import 'dart:async';
 
-import 'package:clide/builtin/claude/src/extension.dart';
 import 'package:clide/builtin/claude/src/session_orchestrator.dart';
 import 'package:clide/builtin/claude/src/stream_json_session.dart';
+import 'package:clide/builtin/claude/src/ticket_pick_up.dart';
 import 'package:clide/clide.dart';
 import 'package:clide/kernel/kernel.dart';
 import 'package:flutter_test/flutter_test.dart';