feat(web): session list one-list, hover card, row menus, rename, manual ordering

Sidebar session list grows the figma 239-10458 feature set and the
workspace/session browsing region moves wholesale into ui-workspace:

- Group-by menu (WorkSpace / In one list): flat mode lists every session
  top-level, strictly newest-first; the choice persists across reloads.
- Session rows get a 500ms hover detail card (title / relative time /
  status line) and a ... menu (Rename / Fork session / Delete session,
  visual-only for now); workspace headers get ... with Rename (wired) and
  Delete workspace (visual-only).
- workspace.rename RPC: trims, rejects duplicate titles on the create
  chain (workspace-name-conflict), no-op on same title; modal dialog with
  client-side duplicate pre-check.
- workspace.insertSessionBefore RPC (DOM-insertBefore semantics, omitted
  anchor appends): HTML5 drag reorder of root sessions inside a workspace
  group; order truth stays host-side, the view refreshes from the
  response/changed frame.
- Activity pinning removed: the session/event touchSession chain is gone;
  workspace accounts are manually owned (new sessions prepend, explicit
  reordering only). Contracts and tests updated, api catalog regenerated.
- ui-sidebar reduced to the column shell (brand, fold state machine, New
  Session, Settings) exposing one sidebar.workspaces hole with a two-fact
  owner share {wide, expandSidebar}; ui-workspace owns the whole region
  (header, search, grouped/flat lists, dialogs, drag) plus the picker via
  a shared WorkspaceCreateFlow. The old sidebar.workspace picker slot and
  its deferral indirection are gone.
- ui-primitives: Menu gains label entries, danger rows, and
  closeOnPointerLeave; new HoverCard (portaled, open-delay, disabled
  guard). Hover card and row menu never coexist.

packages/host/apiproxy/src/api/rpc-map.ts

@@ -19,6 +19,8 @@ export interface RpcMethodMap {
   'host.describe': HostApi['describe']
   'workspace.list': WorkspaceApi['list']
   'workspace.create': WorkspaceApi['create']
+  'workspace.rename': WorkspaceApi['rename']
+  'workspace.insertSessionBefore': WorkspaceApi['insertSessionBefore']
 }
 
 /** Business request payload of method K (reaches through the RpcRequest narrow form to payload). */

packages/host/apiproxy/src/api/rpc.schema.ts

@@ -40,6 +40,7 @@ export const rpcErrorSchema: z.ZodType<RpcError> = z.discriminatedUnion('code',
   z.object({ code: z.literal('workspace-not-found'), message: z.string(), details: z.object({ workspaceId: z.string() }) }),
   z.object({ code: z.literal('workspace-invalid-path'), message: z.string(), details: z.object({ path: z.string() }) }),
   z.object({ code: z.literal('workspace-name-conflict'), message: z.string(), details: z.object({ name: z.string() }) }),
+  z.object({ code: z.literal('workspace-move-invalid'), message: z.string(), details: z.object({ workspaceId: z.string(), sessionId: z.string(), beforeSessionId: z.string().optional() }) }),
   z.object({ code: z.literal('agent-busy'), message: z.string(), details: z.object({ reason: z.string() }) }),
   z.object({ code: z.literal('internal'), message: z.string(), details: z.object({}) }),
 ]) as unknown as z.ZodType<RpcError>

packages/host/apiproxy/src/api/rpc.ts

@@ -37,6 +37,7 @@ export interface RpcErrorDetailsMap {
   'workspace-not-found': { workspaceId: string }
   'workspace-invalid-path': { path: string }
   'workspace-name-conflict': { name: string }
+  'workspace-move-invalid': { workspaceId: string; sessionId: SessionId; beforeSessionId?: SessionId }
   'agent-busy': { reason: string }
   'internal': {}
 }

packages/host/apiproxy/src/api/workspace.schema.ts

@@ -44,3 +44,29 @@ export const workspaceCreateValueSchema = z.object({
   workspace: workspaceViewSchema,
   created: z.boolean(),
 }) satisfies z.ZodType<Wire<ResponseValue<'workspace.create'>>>
+
+/** workspace.rename request payload: the new title must be non-blank. */
+export const workspaceRenameRequestSchema = z.object({
+  workspaceId: workspaceIdSchema,
+  title: z.string(),
+}).refine(
+  payload => payload.title.trim() !== '',
+  { message: 'workspace.rename requires a non-blank title' },
+) satisfies z.ZodType<Wire<RequestPayload<'workspace.rename'>>>
+
+/** workspace.rename response value. */
+export const workspaceRenameValueSchema = z.object({
+  workspace: workspaceViewSchema,
+}) satisfies z.ZodType<Wire<ResponseValue<'workspace.rename'>>>
+
+/** workspace.insertSessionBefore request payload (anchor omitted = append to end). */
+export const workspaceInsertSessionBeforeRequestSchema = z.object({
+  workspaceId: workspaceIdSchema,
+  sessionId: sessionIdSchema,
+  beforeSessionId: sessionIdSchema.optional(),
+}) satisfies z.ZodType<Wire<RequestPayload<'workspace.insertSessionBefore'>>>
+
+/** workspace.insertSessionBefore response value. */
+export const workspaceInsertSessionBeforeValueSchema = z.object({
+  workspace: workspaceViewSchema,
+}) satisfies z.ZodType<Wire<ResponseValue<'workspace.insertSessionBefore'>>>

packages/host/apiproxy/src/api/workspace.ts

@@ -24,7 +24,10 @@ export interface WorkspaceView {
   path: string
   /** Unique display title (defaults to the path basename at create). */
   title: string
-  /** Sessions accounted under this workspace, newest-first for display. */
+  /**
+   * Sessions accounted under this workspace, in manually owned order
+   * (attach prepends, insertSessionBefore reorders; activity never does).
+   */
   sessionIds: SessionId[]
   /** ISO-8601 creation instant. */
   createdAt: string
@@ -52,4 +55,27 @@ export interface WorkspaceApi {
    */
   create(request: RpcRequest<{ path?: string; name?: string }>):
   Promise<RpcResponse<{ workspace: WorkspaceView; created: boolean }>>
+
+  /**
+   * Renames a workspace. `title` is trimmed and must be non-empty
+   * (schema-enforced). An unknown id fails with `workspace-not-found`; a
+   * title equal to another workspace's fails with `workspace-name-conflict`.
+   * Renaming to the current title is a no-op success (no durable write).
+   */
+  rename(request: RpcRequest<{ workspaceId: WorkspaceId; title: string }>):
+  Promise<RpcResponse<{ workspace: WorkspaceView }>>
+
+  /**
+   * Moves an accounted session within its workspace's manual order,
+   * DOM-insertBefore-like: with `beforeSessionId` the session is inserted
+   * before that anchor; omitted appends to the end. An unknown workspace
+   * fails with `workspace-not-found`; a session or anchor not accounted by
+   * the workspace fails with `workspace-move-invalid`. A move to the current
+   * position is a no-op success.
+   */
+  insertSessionBefore(request: RpcRequest<{
+    workspaceId: WorkspaceId
+    sessionId: SessionId
+    beforeSessionId?: SessionId
+  }>): Promise<RpcResponse<{ workspace: WorkspaceView }>>
 }