diff --git a/web/workspace/deno.json b/web/workspace/deno.json
index c3a7acf36..3b9e7853b 100644
--- a/web/workspace/deno.json
+++ b/web/workspace/deno.json
@@ -6,7 +6,7 @@
     "dev": "deno run -A npm:vite@7.2.7 dev",
     "dev:backend": "cd ../.. && cargo run -p yoi-workspace-server --bin yoi-server -- serve --listen 127.0.0.1:8787",
     "check": "deno run -A npm:@sveltejs/kit@2.49.4 sync && deno run -A npm:svelte-check@4.3.4 --tsconfig ./tsconfig.json",
-    "test": "deno test --allow-read=src,test,tests,../../docs --allow-env=LOG,VSCODE_TEXTMATE_DEBUG,NODE_ENV tests/workspace-model.test.ts tests/repository-api.test.ts tests/workspace-catalog.test.ts tests/profile-api.test.ts tests/skill-api.test.ts tests/tooltip-contract.test.ts tests/bevel-contract.test.ts tests/bevel-line-contract.test.ts tests/typography-contract.test.ts src/lib/workspace/auth/model.test.ts tests/auth-api.test.ts src/lib/workspace/api/http.test.ts src/lib/workspace/api/workers.test.ts src/lib/workspace/header/breadcrumb-model.test.ts src/lib/workspace/console/chat-submit.test.ts src/lib/workspace/console/composer-delivery.test.ts test/composer-history.test.ts tests/composer-paste.test.ts src/lib/workspace/console/composer-command.test.ts src/lib/workspace/console/composer-draft.test.ts src/lib/workspace/console/composer-completion.test.ts test/console/ansi.test.ts src/lib/workspace/console/model.test.ts src/lib/workspace/console/run-status.test.ts src/lib/workspace/companion/api.test.ts tests/workdir-api.test.ts src/lib/workspace/console/tasks.test.ts test/ticket-detail-route-reuse.test.ts test/objective-pages.test.ts test/repositories/ui.test.ts src/lib/workspace/console/worker-console.ui.test.ts src/lib/workspace/settings/model.test.ts tests/runtime-connection.test.ts tests/runtime-management.test.ts tests/runtime-management-source.test.ts src/lib/workspace/sidebar/override-stack.test.ts src/lib/workspace/sidebar/workers.test.ts src/lib/workspace/sidebar/workspace-switcher.test.ts src/lib/workspace/sidebar/worker-subscription.test.ts src/lib/workspace/sidebar/worker-launch.test.ts test/sidebar/worker-actions.test.ts src/lib/workspace/tickets/merge-request-resources.test.ts src/lib/workspace/tickets/ticket-panel.test.ts test/merge-request-status.test.ts test/config-source/decodal-grammar.test.ts test/config-source/editor-state.test.ts test/config-source/fixed-schema-wrapper.test.ts test/config-source/toolchain.test.ts test/config-source/wasm-parity.test.ts test/repository-access/api.test.ts test/repository-access/loader.test.ts test/repository-access/ui.test.ts test/repository-ssh-connection-ui.test.ts",
+    "test": "deno test --allow-read=src,test,tests,../../docs --allow-env=LOG,VSCODE_TEXTMATE_DEBUG,NODE_ENV tests/workspace-model.test.ts tests/repository-api.test.ts tests/workspace-catalog.test.ts tests/profile-api.test.ts tests/skill-api.test.ts tests/tooltip-contract.test.ts tests/bevel-contract.test.ts tests/bevel-line-contract.test.ts tests/typography-contract.test.ts src/lib/workspace/auth/model.test.ts tests/auth-api.test.ts src/lib/workspace/api/http.test.ts src/lib/workspace/api/workers.test.ts src/lib/workspace/header/breadcrumb-model.test.ts src/lib/workspace/console/chat-submit.test.ts src/lib/workspace/console/composer-delivery.test.ts test/composer-history.test.ts tests/composer-paste.test.ts src/lib/workspace/console/composer-command.test.ts src/lib/workspace/console/composer-draft.test.ts src/lib/workspace/console/composer-completion.test.ts test/console/ansi.test.ts src/lib/workspace/console/model.test.ts src/lib/workspace/console/run-status.test.ts src/lib/workspace/companion/api.test.ts tests/workdir-api.test.ts src/lib/workspace/console/tasks.test.ts test/ticket-detail-route-reuse.test.ts test/objective-pages.test.ts test/repositories/ui.test.ts src/lib/workspace/console/worker-console.ui.test.ts src/lib/workspace/settings/model.test.ts tests/runtime-connection.test.ts tests/runtime-management.test.ts tests/runtime-management-source.test.ts src/lib/workspace/sidebar/override-stack.test.ts src/lib/workspace/sidebar/workers.test.ts src/lib/workspace/sidebar/workspace-switcher.test.ts src/lib/workspace/sidebar/worker-subscription.test.ts src/lib/workspace/sidebar/worker-workdir-meta.test.ts src/lib/workspace/sidebar/worker-launch.test.ts test/sidebar/worker-actions.test.ts src/lib/workspace/tickets/merge-request-resources.test.ts src/lib/workspace/tickets/ticket-panel.test.ts test/merge-request-status.test.ts test/config-source/decodal-grammar.test.ts test/config-source/editor-state.test.ts test/config-source/fixed-schema-wrapper.test.ts test/config-source/toolchain.test.ts test/config-source/wasm-parity.test.ts test/repository-access/api.test.ts test/repository-access/loader.test.ts test/repository-access/ui.test.ts test/repository-ssh-connection-ui.test.ts",
     "test:component": "deno run -A npm:vitest@3.2.4 run --config vitest.config.ts",
     "build": "deno run -A npm:vite@7.2.7 build",
     "preview": "deno run -A npm:vite@7.2.7 preview",
diff --git a/web/workspace/src/lib/workspace/console/worker-console.ui.test.ts b/web/workspace/src/lib/workspace/console/worker-console.ui.test.ts
index 774df4ab1..5f5094f8f 100644
--- a/web/workspace/src/lib/workspace/console/worker-console.ui.test.ts
+++ b/web/workspace/src/lib/workspace/console/worker-console.ui.test.ts
@@ -219,6 +219,9 @@ Deno.test("workspace Worker list lives on the dedicated Workers page", async ()
   const workersNav = await Deno.readTextFile(
     new URL("../sidebar/WorkersNavSection.svelte", import.meta.url),
   );
+  const workerWorkdirMeta = await Deno.readTextFile(
+    new URL("../sidebar/worker-workdir-meta.ts", import.meta.url),
+  );
   const sidebar = await Deno.readTextFile(
     new URL("../sidebar/WorkspaceSidebar.svelte", import.meta.url),
   );
@@ -256,12 +259,18 @@ Deno.test("workspace Worker list lives on the dedicated Workers page", async ()
       workersNav.includes("worker.display_name || worker.label") &&
       workersNav.includes("worker-status-dot") &&
       workersNav.includes("worker-status-spinner") &&
-      workersNav.includes("workdirMeta(worker)") &&
-      workersNav.includes("attachment.alias") &&
-      workersNav.includes("attachment.repository_key ?? '—'") &&
-      workersNav.includes("attachment.working_directory_id") &&
+      workersNav.includes("sidebarWorkdirMeta(worker.workdir_attachments)") &&
+      workersNav.includes("title={workdir.details}") &&
+      !workersNav.includes("attachment.alias") &&
+      workerWorkdirMeta.includes("workdir.current_selector") &&
+      workerWorkdirMeta.includes("workdir.creation_selector") &&
+      workerWorkdirMeta.includes("explicitReferenceFallback(") &&
+      workerWorkdirMeta.includes('"detached"') &&
+      sidebarCss.includes(".worker-nav-meta") &&
+      sidebarCss.includes("text-overflow: ellipsis") &&
+      sidebarCss.includes("white-space: nowrap") &&
       !workersNav.includes('aria-disabled="true"'),
-    "Workers sidebar should link to the Worker list page and show state indicators with repository/workdir metadata",
+    "Workers sidebar should show truncated repo:branch Workdir metadata with detached fallback and detail-only attachment identifiers",
   );
   assert(
     workersNav.includes("COLLAPSED_WORKER_COUNT = 6") &&
diff --git a/web/workspace/src/lib/workspace/sidebar/WorkersNavSection.svelte b/web/workspace/src/lib/workspace/sidebar/WorkersNavSection.svelte
index 3260def2e..6adcb63c5 100644
--- a/web/workspace/src/lib/workspace/sidebar/WorkersNavSection.svelte
+++ b/web/workspace/src/lib/workspace/sidebar/WorkersNavSection.svelte
@@ -12,6 +12,7 @@
     type SidebarWorker,
   } from './worker-subscription';
   import { canShowWorkerInSidebar, sidebarWorkerActivity } from './workers';
+  import { sidebarWorkdirMeta } from './worker-workdir-meta';
 
   const COLLAPSED_WORKER_COUNT = 6;
   type WorkerActionKind = 'stop' | 'delete';
@@ -37,14 +38,6 @@
     Math.max(0, workers.length - COLLAPSED_WORKER_COUNT),
   );
 
-  function workdirMeta(worker: SidebarWorker): string {
-    const attachments = worker.workdir_attachments;
-    if (attachments.length === 0) return '—';
-    return attachments
-      .map((attachment) => `${attachment.alias}: ${attachment.repository_key ?? '—'}・${attachment.working_directory_id}`)
-      .join(', ');
-  }
-
   function workerKey(worker: SidebarWorker): string {
     return `${worker.runtime_id}:${worker.worker_id}`;
   }
@@ -180,6 +173,7 @@
         {@const activity = sidebarWorkerActivity(worker)}
         {@const key = workerKey(worker)}
         {@const label = worker.display_name || worker.label}
+        {@const workdir = sidebarWorkdirMeta(worker.workdir_attachments)}
         <li class="worker-nav-item" data-worker-actions={key}>
           <a
             href={href}
@@ -197,8 +191,8 @@
               {/if}
             </span>
             <span class="worker-nav-label">{label}</span>
-            <small class="worker-nav-meta">
-              {workdirMeta(worker)}
+            <small class="worker-nav-meta" title={workdir.details} aria-label={workdir.details}>
+              {workdir.text}
             </small>
           </a>
           <button
diff --git a/web/workspace/src/lib/workspace/sidebar/worker-subscription.ts b/web/workspace/src/lib/workspace/sidebar/worker-subscription.ts
index c4b8aebba..848213684 100644
--- a/web/workspace/src/lib/workspace/sidebar/worker-subscription.ts
+++ b/web/workspace/src/lib/workspace/sidebar/worker-subscription.ts
@@ -1,19 +1,20 @@
-import { readable, type Readable } from 'svelte/store';
-import type {
-  SubscriptionWorker,
-  SubscriptionWorkerWorkdirAttachment,
-} from '$lib/generated/protocol';
-import { workspaceMultiplexer } from '$lib/workspace/multiplexer';
+import { type Readable, readable } from "svelte/store";
+import type { WorkingDirectorySummary } from "$lib/generated/workdir-api";
+import type { SubscriptionWorker } from "$lib/generated/protocol";
+import { loadJson, workspaceApiPath } from "$lib/workspace/api/http";
+import { parseWorkingDirectoryListResponse } from "$lib/workspace/api/workdirs";
+import { workspaceMultiplexer } from "$lib/workspace/multiplexer";
 import {
   applyWorkspaceWorkersFrame,
   createWorkspaceWorkersProjection,
-} from './worker-subscription-model';
-import { liveWorkerState } from './worker-state';
-import { compareWorkersForSidebar } from './workers';
-import type { Worker } from './types';
+} from "./worker-subscription-model";
+import { liveWorkerState } from "./worker-state";
+import type { SidebarWorkdirAttachment } from "./worker-workdir-meta";
+import { compareWorkersForSidebar } from "./workers";
+import type { Worker } from "./types";
 
-export type SidebarWorker = Omit<Worker, 'workdir_attachments'> & {
-  workdir_attachments: SubscriptionWorkerWorkdirAttachment[];
+export type SidebarWorker = Omit<Worker, "workdir_attachments"> & {
+  workdir_attachments: SidebarWorkdirAttachment[];
   has_running_internal_workers: boolean;
 };
 
@@ -29,7 +30,9 @@ export function disposeWorkspaceWorkersStore(workspaceId: string): void {
   stores.delete(workspaceId);
 }
 
-export function workspaceWorkersStore(workspaceId: string): Readable<WorkspaceWorkersState> {
+export function workspaceWorkersStore(
+  workspaceId: string,
+): Readable<WorkspaceWorkersState> {
   const cached = stores.get(workspaceId);
   if (cached) return cached;
   const store = readable<WorkspaceWorkersState>(
@@ -40,48 +43,113 @@ export function workspaceWorkersStore(workspaceId: string): Readable<WorkspaceWo
         return;
       }
       const projection = createWorkspaceWorkersProjection();
-      const publish = (loading = false, error: string | null = null) => {
+      let workdirs = new Map<string, WorkingDirectorySummary>();
+      let loading = true;
+      let error: string | null = null;
+      let disposed = false;
+      let workdirRequest = 0;
+      const publish = () => {
         const workers = [...projection.workers.values()]
-          .map(projectWorker)
+          .map((worker) => projectWorker(worker, workdirs))
           .sort(compareWorkersForSidebar);
         set({ loading, error, workers });
       };
-      const subscription = workspaceMultiplexer(workspaceId).subscribe(
-        { topic: 'workspace_workers' },
+      const refreshWorkdirs = async () => {
+        const request = ++workdirRequest;
+        const result = await loadJson(
+          fetch,
+          workspaceApiPath(workspaceId, "/working-directories"),
+          undefined,
+          parseWorkingDirectoryListResponse,
+        );
+        if (disposed || request !== workdirRequest || !result.data) return;
+        workdirs = new Map(
+          result.data.items.map((
+            workdir,
+          ) => [workdir.working_directory_id, workdir]),
+        );
+        publish();
+      };
+      const multiplexer = workspaceMultiplexer(workspaceId);
+      const subscription = multiplexer.subscribe(
+        { topic: "workspace_workers" },
         {
           onFrame: (frame) => {
             try {
-              if (frame.frame === 'event' && frame.message.event === 'subscription_closed') {
+              if (
+                frame.frame === "event" &&
+                frame.message.event === "subscription_closed"
+              ) {
                 throw new Error(frame.message.data.message);
               }
               if (
-                frame.frame === 'response' &&
-                frame.message.result === 'subscription_rejected'
+                frame.frame === "response" &&
+                frame.message.result === "subscription_rejected"
               ) {
                 throw new Error(frame.message.payload.message);
               }
               applyWorkspaceWorkersFrame(projection, frame);
-              publish(false, null);
-            } catch (error) {
-              publish(false, error instanceof Error ? error.message : 'invalid Worker subscription frame');
+              loading = false;
+              error = null;
+              publish();
+            } catch (cause) {
+              loading = false;
+              error = cause instanceof Error
+                ? cause.message
+                : "invalid Worker subscription frame";
+              publish();
             }
           },
           onStatus: (status, message) => {
-            if (status === 'connecting') publish(projection.workers.size === 0, null);
-            if (status === 'closed') publish(projection.workers.size === 0, message ?? null);
+            if (status === "connecting") {
+              loading = projection.workers.size === 0;
+              error = null;
+              publish();
+            }
+            if (status === "closed") {
+              loading = projection.workers.size === 0;
+              error = message ?? null;
+              publish();
+            }
           },
         },
       );
-      return () => subscription.close();
+      const workdirSubscription = multiplexer.subscribe(
+        { topic: "workspace_workdirs" },
+        {
+          onFrame: (frame) => {
+            const isSnapshot = frame.frame === "response" &&
+              frame.message.result === "subscribed";
+            const isUpdate = frame.frame === "event" &&
+              frame.message.event === "event" &&
+              (frame.message.data.payload.event === "workdir_upserted" ||
+                frame.message.data.payload.event === "workdir_removed");
+            if (isSnapshot || isUpdate) void refreshWorkdirs();
+          },
+        },
+      );
+      void refreshWorkdirs();
+      return () => {
+        disposed = true;
+        subscription.close();
+        workdirSubscription.close();
+      };
     },
   );
   stores.set(workspaceId, store);
   return store;
 }
 
-function projectWorker(worker: SubscriptionWorker): SidebarWorker {
-  if (!worker.runtime_id) throw new Error('Workspace Worker projection is missing runtime_id');
-  if (!worker.resource_key) throw new Error('Workspace Worker projection is missing resource_key');
+function projectWorker(
+  worker: SubscriptionWorker,
+  workdirs: ReadonlyMap<string, WorkingDirectorySummary>,
+): SidebarWorker {
+  if (!worker.runtime_id) {
+    throw new Error("Workspace Worker projection is missing runtime_id");
+  }
+  if (!worker.resource_key) {
+    throw new Error("Workspace Worker projection is missing resource_key");
+  }
   const displayName = worker.display_name ?? `Worker ${worker.worker_id}`;
   return {
     runtime_id: worker.runtime_id,
@@ -92,20 +160,29 @@ function projectWorker(worker: SubscriptionWorker): SidebarWorker {
     label: displayName,
     profile: worker.profile ?? null,
     tags: [],
-    workspace: { visibility: 'workspace', identity: 'runtime_subscription_worker' },
+    workspace: {
+      visibility: "workspace",
+      identity: "runtime_subscription_worker",
+    },
     state: liveWorkerState(worker),
     worker_state: worker.worker_state,
     pinned: false,
-    retention_state: 'transient',
+    retention_state: "transient",
     implementation: {
-      kind: 'runtime_subscription_worker',
-      display_hint: 'Workspace-authorized Runtime Worker',
+      kind: "runtime_subscription_worker",
+      display_hint: "Workspace-authorized Runtime Worker",
     },
     capabilities: {
-      can_stop: worker.availability !== 'unavailable' && worker.state !== 'stopped',
+      can_stop: worker.availability !== "unavailable" &&
+        worker.state !== "stopped",
       can_spawn_followup: false,
     },
-    workdir_attachments: worker.workdir_attachments ?? [],
+    workdir_attachments: (worker.workdir_attachments ?? []).map((
+      attachment,
+    ) => ({
+      ...attachment,
+      working_directory: workdirs.get(attachment.working_directory_id),
+    })),
     has_running_internal_workers: worker.has_running_internal_workers,
     diagnostics: [],
   };
diff --git a/web/workspace/src/lib/workspace/sidebar/worker-workdir-meta.test.ts b/web/workspace/src/lib/workspace/sidebar/worker-workdir-meta.test.ts
new file mode 100644
index 000000000..26303f97b
--- /dev/null
+++ b/web/workspace/src/lib/workspace/sidebar/worker-workdir-meta.test.ts
@@ -0,0 +1,116 @@
+import type { WorkingDirectorySummary } from "$lib/generated/workdir-api";
+import {
+  type SidebarWorkdirAttachment,
+  sidebarWorkdirMeta,
+} from "./worker-workdir-meta.ts";
+
+function assertEquals(actual: unknown, expected: unknown): void {
+  if (JSON.stringify(actual) !== JSON.stringify(expected)) {
+    throw new Error(
+      `expected ${JSON.stringify(expected)}, got ${JSON.stringify(actual)}`,
+    );
+  }
+}
+
+function assert(condition: boolean, message: string): void {
+  if (!condition) throw new Error(message);
+}
+
+declare const Deno: {
+  test(name: string, fn: () => void | Promise<void>): void;
+};
+
+function workdir(
+  overrides: Partial<WorkingDirectorySummary> = {},
+): WorkingDirectorySummary {
+  return {
+    working_directory_id: "workdir-1234567890abcdef",
+    repository_key: "main",
+    materializer_kind: "runtime_git_clone",
+    status: "active",
+    ...overrides,
+  };
+}
+
+function attachment(
+  alias: string,
+  overrides: Partial<WorkingDirectorySummary> = {},
+): SidebarWorkdirAttachment {
+  const workingDirectory = workdir(overrides);
+  return {
+    alias,
+    repository_key: workingDirectory.repository_key,
+    working_directory_id: workingDirectory.working_directory_id,
+    working_directory: workingDirectory,
+  };
+}
+
+Deno.test("Worker sidebar Workdir label prefers the current branch selector", () => {
+  const meta = sidebarWorkdirMeta([
+    attachment("checkout", {
+      creation_selector: "develop",
+      current_selector: "refs/heads/work/T-642-sidebar",
+      current_ref: "0123456789abcdef0123456789abcdef01234567",
+    }),
+  ]);
+
+  assertEquals(meta.text, "main:work/T-642-sidebar");
+  assert(
+    meta.details.includes("checkout — main:work/T-642-sidebar"),
+    "attachment alias should remain available in details",
+  );
+  assert(
+    meta.details.includes("Workdir workdir-1234567890abcdef"),
+    "opaque Workdir id should remain available in details",
+  );
+});
+
+Deno.test("Worker sidebar Workdir label uses the creation branch before observation", () => {
+  const meta = sidebarWorkdirMeta([
+    attachment("checkout", { creation_selector: "develop" }),
+  ]);
+
+  assertEquals(meta.text, "main:develop");
+});
+
+Deno.test("Worker sidebar Workdir label marks detached HEAD instead of reusing creation branch", () => {
+  const meta = sidebarWorkdirMeta([
+    attachment("checkout", {
+      creation_selector: "develop",
+      current_ref: "0123456789abcdef0123456789abcdef01234567",
+    }),
+  ]);
+
+  assertEquals(meta.text, "main:detached@0123456789ab");
+});
+
+Deno.test("Worker sidebar Workdir label has an explicit unknown fallback", () => {
+  const meta = sidebarWorkdirMeta([{
+    alias: "checkout",
+    repository_key: "main",
+    working_directory_id: "workdir-1234567890abcdef",
+  }]);
+
+  assertEquals(meta.text, "main:unknown@workdir-1234");
+});
+
+Deno.test("Worker sidebar Workdir metadata keeps multiple attachments distinguishable", () => {
+  const meta = sidebarWorkdirMeta([
+    attachment("frontend", { current_selector: "develop" }),
+    attachment("backend", {
+      working_directory_id: "workdir-fedcba0987654321",
+      repository_key: "server",
+      current_selector: "release",
+    }),
+  ]);
+
+  assertEquals(meta.text, "main:develop · server:release");
+  assert(
+    meta.details.includes("frontend — main:develop"),
+    "first alias should be in details",
+  );
+  assert(
+    meta.details.includes("backend — server:release"),
+    "second alias should be in details",
+  );
+});
diff --git a/web/workspace/src/lib/workspace/sidebar/worker-workdir-meta.ts b/web/workspace/src/lib/workspace/sidebar/worker-workdir-meta.ts
new file mode 100644
index 000000000..7451eb818
--- /dev/null
+++ b/web/workspace/src/lib/workspace/sidebar/worker-workdir-meta.ts
@@ -0,0 +1,115 @@
+import type { WorkingDirectorySummary } from "$lib/generated/workdir-api";
+import type { SubscriptionWorkerWorkdirAttachment } from "$lib/generated/protocol";
+
+const SHORT_REFERENCE_LENGTH = 12;
+
+export type SidebarWorkdirAttachment = SubscriptionWorkerWorkdirAttachment & {
+  working_directory?: WorkingDirectorySummary;
+};
+
+export type SidebarWorkdirMeta = {
+  text: string;
+  details: string;
+};
+
+export function sidebarWorkdirMeta(
+  attachments: readonly SidebarWorkdirAttachment[],
+): SidebarWorkdirMeta {
+  if (attachments.length === 0) {
+    return { text: "—", details: "No Workdir attachments" };
+  }
+
+  return {
+    text: attachments.map(attachmentLabel).join(" · "),
+    details: attachments.map(attachmentDetails).join("\n"),
+  };
+}
+
+function attachmentLabel(attachment: SidebarWorkdirAttachment): string {
+  const workdir = attachment.working_directory;
+  const repository = clean(workdir?.repository_key) ??
+    clean(attachment.repository_key) ?? "unknown-repo";
+  return `${repository}:${revisionLabel(attachment)}`;
+}
+
+function revisionLabel(attachment: SidebarWorkdirAttachment): string {
+  const workdir = attachment.working_directory;
+  if (!workdir) {
+    return `unknown@${shortReference(attachment.working_directory_id)}`;
+  }
+
+  const currentSelector = clean(workdir.current_selector);
+  const currentBranch = branchName(currentSelector);
+  if (currentBranch) return currentBranch;
+
+  const currentReference = clean(workdir.current_ref);
+  if (currentSelector || currentReference) {
+    return explicitReferenceFallback(
+      "detached",
+      currentReference ?? currentSelector,
+    );
+  }
+
+  const creationSelector = clean(workdir.creation_selector);
+  const creationBranch = branchName(creationSelector);
+  if (creationBranch) return creationBranch;
+
+  const creationReference = clean(workdir.creation_ref);
+  if (creationSelector || creationReference) {
+    return explicitReferenceFallback(
+      "revision",
+      creationReference ?? creationSelector,
+    );
+  }
+
+  return `unknown@${shortReference(attachment.working_directory_id)}`;
+}
+
+function branchName(selector: string | null): string | null {
+  if (!selector || selector === "HEAD" || isHash(selector)) return null;
+  if (selector.startsWith("refs/heads/")) {
+    return clean(selector.slice("refs/heads/".length));
+  }
+  if (selector.startsWith("refs/")) return null;
+  return selector;
+}
+
+function explicitReferenceFallback(
+  kind: "detached" | "revision",
+  reference: string | null,
+): string {
+  return reference ? `${kind}@${shortReference(reference)}` : kind;
+}
+
+function attachmentDetails(attachment: SidebarWorkdirAttachment): string {
+  const workdir = attachment.working_directory;
+  const details = [
+    `${attachment.alias} — ${attachmentLabel(attachment)}`,
+    `Workdir ${attachment.working_directory_id}`,
+  ];
+  if (clean(workdir?.current_selector)) {
+    details.push(`Current selector ${workdir?.current_selector?.trim()}`);
+  }
+  if (clean(workdir?.current_ref)) {
+    details.push(`Current ref ${workdir?.current_ref?.trim()}`);
+  }
+  if (clean(workdir?.creation_selector)) {
+    details.push(`Creation selector ${workdir?.creation_selector?.trim()}`);
+  }
+  return details.join(" · ");
+}
+
+function clean(value: string | null | undefined): string | null {
+  const cleaned = value?.trim();
+  return cleaned ? cleaned : null;
+}
+
+function shortReference(reference: string): string {
+  return reference.length > SHORT_REFERENCE_LENGTH
+    ? reference.slice(0, SHORT_REFERENCE_LENGTH)
+    : reference;
+}
+
+function isHash(value: string): boolean {
+  return /^[0-9a-f]{7,64}$/i.test(value);
+}