fix(desktop,tui,docs): dedup commands.catalog, route desktop /compact to /compress, update README

- tui_gateway commands.catalog: skip _TUI_EXTRA entries that collide with a
  registry command or alias (the /compact class of bug, #57133; also removes
  the pre-existing /sessions duplicate) — registry entry is canonical.
- apps/desktop: /compact now dispatches as an alias of /compress (matching
  the registry's canonical alias) instead of dead-ending; /density (the
  renamed TUI display toggle) is marked terminal-only so the desktop palette
  doesn't advertise a command its dispatcher can't run.
- ui-tui/README.md: document /density instead of the old /compact toggle.
- tests: commands.catalog regression test asserting no duplicate advertised
  names and no command shadowing another command's alias; desktop routing test.

apps/desktop/src/lib/desktop-slash-commands.test.ts

@@ -31,7 +31,7 @@ describe('desktop slash command curation', () => {
 
   it('hides terminal, messaging, and dedicated-UI commands from suggestions', () => {
     expect(isDesktopSlashSuggestion('/clear')).toBe(false)
-    expect(isDesktopSlashSuggestion('/compact')).toBe(false)
+    expect(isDesktopSlashSuggestion('/density')).toBe(false)
     expect(isDesktopSlashSuggestion('/redraw')).toBe(false)
     expect(isDesktopSlashSuggestion('/approve')).toBe(false)
     expect(isDesktopSlashSuggestion('/model')).toBe(false)
@@ -40,6 +40,14 @@ describe('desktop slash command curation', () => {
     expect(isDesktopSlashSuggestion('/curator')).toBe(false)
   })
 
+  it('routes /compact to /compress (context compression), not the TUI display toggle', () => {
+    expect(resolveDesktopCommand('/compact')?.name).toBe('/compress')
+    expect(isDesktopSlashCommand('/compact')).toBe(true)
+    // Alias stays out of the popover so /compress is the single visible entry.
+    expect(isDesktopSlashSuggestion('/compact')).toBe(false)
+    expect(isDesktopSlashSuggestion('/compress')).toBe(true)
+  })
+
   it('surfaces /tools, /save, and /personality on the desktop', () => {
     expect(isDesktopSlashSuggestion('/tools')).toBe(true)
     expect(isDesktopSlashSuggestion('/save')).toBe(true)

apps/desktop/src/lib/desktop-slash-commands.ts

@@ -148,7 +148,7 @@ const DESKTOP_COMMAND_SPECS: readonly DesktopCommandSpec[] = [
     surface: exec()
   },
   { name: '/background', description: 'Run a prompt in the background', aliases: ['/bg', '/btw'], surface: exec() },
-  { name: '/compress', description: 'Compress this conversation context', surface: exec() },
+  { name: '/compress', description: 'Compress this conversation context', aliases: ['/compact'], surface: exec() },
   { name: '/debug', description: 'Create a debug report', surface: exec() },
   { name: '/goal', description: 'Manage the standing goal for this session', surface: exec() },
   { name: '/personality', description: 'Switch personality for this session', surface: exec(), args: true },
@@ -187,10 +187,10 @@ const NO_DESKTOP_SURFACE: Record<DesktopUnavailableReason, readonly string[]> =
   terminal: [
     '/busy',
     '/clear',
-    '/compact',
     '/config',
     '/copy',
     '/cron',
+    '/density',
     '/details',
     '/exit',
     '/footer',

tests/test_tui_gateway_server.py

@@ -6418,6 +6418,30 @@ def test_commands_catalog_includes_tui_mouse_command():
     assert "/mouse" in tui_pairs
 
 
+def test_commands_catalog_has_no_duplicate_or_alias_colliding_names():
+    """No command may be advertised twice, and no advertised command may
+    shadow an alias of a different command (e.g. the historical /compact
+    collision where the registry aliased compact -> compress while the TUI
+    also registered its own /compact display toggle; see #57133)."""
+    resp = server.handle_request(
+        {"id": "1", "method": "commands.catalog", "params": {}}
+    )
+
+    names = [name for name, _ in resp["result"]["pairs"]]
+    dupes = {n for n in names if names.count(n) > 1}
+    assert not dupes, f"duplicate commands advertised in catalog: {sorted(dupes)}"
+
+    canon = resp["result"]["canon"]
+    colliding = {
+        name
+        for name in names
+        if canon.get(name.lower(), name) != name
+    }
+    assert not colliding, (
+        f"catalog commands shadow aliases of other commands: {sorted(colliding)}"
+    )
+
+
 def test_commands_catalog_filters_gateway_only_commands_and_keeps_status_visible():
     resp = server.handle_request(
         {"id": "1", "method": "commands.catalog", "params": {}}

tui_gateway/server.py

@@ -13342,6 +13342,13 @@ def _(rid, params: dict) -> dict:
             cat_map[cat].append([c, desc])
 
         for name, desc, cat in _TUI_EXTRA:
+            # Dedup guard: skip TUI extras that collide with a registry
+            # command or one of its aliases (e.g. the historical /compact
+            # collision, #57133, or /sessions which the registry also
+            # advertises). The registry entry is canonical.
+            if name.lower() in canon:
+                continue
+            canon[name.lower()] = name
             all_pairs.append([name, desc])
             if cat not in cat_map:
                 cat_map[cat] = []

ui-tui/README.md

@@ -225,7 +225,7 @@ The following commands are handled directly by the TUI client. Unrecognized comm
 
 ### Core (`core.ts`)
 `/help`, `/quit` (alias `/exit`), `/update`, `/clear` (alias `/new`),
-`/compact`, `/copy`, `/paste`, `/details` (alias `/detail`),
+`/density`, `/copy`, `/paste`, `/details` (alias `/detail`),
 `/statusbar` (alias `/sb`), `/queue` (alias `/q`), `/logs`, `/history`,
 `/save`, `/undo`, `/retry`, `/steer`, `/mouse` (alias `/scroll`),
 `/status`, `/title`, `/fortune`, `/redraw`, `/terminal-setup`