feat(ui): a Claude-Desktop-style home for every workspace

/workspace?lane=<id> opens on the workspace's home (WorkspaceHome): a prompt
box whose Start opens a new session in the first free pane slot, Recents (a
live session attaches its pane, any other opens its transcript, nothing
resumes), and Instructions / Memory / Context / Folder. Instructions live in
lanes.instructions, extra folders and uploaded files in the new lane_sources
table (copies under <data dir>/workspace-context/<lane id>/); spawnRun reads
them from the lane's rows and hands Claude --add-dir + an appended system
prompt file, Codex --add-dir + developer_instructions. Memory is read-only.

Every dashboard pane carries AGENTHUB_RUN_ID; hooks forward it and the run
records which session the pane holds (a Claude pane follows /clear and
/resume but not a nested claude -p), so the sidebar and notifications open
the right pane (&run=). Settings loses its Projects group; Worktrees now
decides which worktrees Add folder suggests.

client/src/lib/projectTreePrefs.ts

@@ -1,11 +1,10 @@
 /**
  * @file projectTreePrefs — the sidebar workspace list's viewer preferences, in
  * ONE localStorage key (`agenthub.sidebar.projects`): which workspaces are
- * expanded to their sessions (by lane id), whether a repo's untracked
- * worktrees are offered, and which
- * worktree sources (`claude` = `<repo>/.claude/worktrees/*`, `agenthub` =
- * LANES_ROOT) are hidden — globally, or per project root, where a project's own
- * list (Settings → Projects) replaces the global one. A `useSyncExternalStore` reader that caches nothing
+ * expanded to their sessions (by lane id), and — Settings → Worktrees —
+ * whether a workspace home's Add folder suggests the repo's untracked
+ * worktrees and which sources of them (`claude` = `<repo>/.claude/worktrees/*`,
+ * `agenthub` = LANES_ROOT) it leaves out. A `useSyncExternalStore` reader that caches nothing
  * but the parsed blob for the current raw string, so the sidebar and Settings
  * can never disagree. Nothing here reaches the server.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
@@ -20,15 +19,12 @@ export interface ProjectTreePrefs {
   expanded: Record<string, boolean>;
   showUntracked: boolean;
   hideSources: string[];
-  /** Per project root: replaces `hideSources` for that project. */
-  projectHideSources: Record<string, string[]>;
 }
 
 const DEFAULTS: ProjectTreePrefs = {
   expanded: {},
   showUntracked: true,
   hideSources: [],
-  projectHideSources: {},
 };
 const listeners = new Set<() => void>();
 let cache: { raw: string | null; value: ProjectTreePrefs } = { raw: null, value: DEFAULTS };
@@ -51,10 +47,6 @@ export function readProjectTreePrefs(): ProjectTreePrefs {
       expanded: parsed.expanded && typeof parsed.expanded === "object" ? parsed.expanded : {},
       showUntracked: parsed.showUntracked !== false,
       hideSources: Array.isArray(parsed.hideSources) ? parsed.hideSources : [],
-      projectHideSources:
-        parsed.projectHideSources && typeof parsed.projectHideSources === "object"
-          ? parsed.projectHideSources
-          : {},
     };
   } catch {
     value = DEFAULTS;
@@ -72,11 +64,6 @@ export function writeProjectTreePrefs(patch: Partial<ProjectTreePrefs>): void {
   listeners.forEach((l) => l());
 }
 
-/** The sources hidden for one project: its own override, else the global list. */
-export function hiddenSourcesFor(prefs: ProjectTreePrefs, root: string | null): string[] {
-  return (root !== null && prefs.projectHideSources[root]) || prefs.hideSources;
-}
-
 function subscribe(l: () => void) {
   listeners.add(l);
   return () => listeners.delete(l);