feat: composer-centric UI refresh + Hermes Control Center (v0.50.0, closes #242)

* Polish workspace panel behavior and app dialogs

* Replace remaining emoji UI glyphs with Lucide icons

* Redesign composer footer around model and context controls

Move the model selector into the composer footer, replace the linear context pill with a compact circular badge plus tooltip, and remove the redundant topbar model pill.

Design credit and inspiration: Theo / T3 Code.
Reference implementation: https://github.com/pingdotgg/t3code/

* Remove obsolete activity bar

Drop the old activity bar, keep turn-scoped state in the composer footer, and route remaining non-chat status messages through toasts.

This leaves live tool cards and the message timeline as the primary progress UI, with the composer owning stop/cancel and brief turn status.

* Move workspace and model switching into composer footer

* Move profile switching into composer footer

* Refactor Hermes control center UI

* Redesign control center settings modal layout

Widen the modal to 860px, simplify the tab list to icon+label rows,
stretch the tab column's divider to full height, lock the panel to a
fixed height so switching tabs no longer resizes the outer shell, and
always open on the Conversation tab.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Put session item actions in a dropdown

* Use Hermes mark in sidebar control button

* Reset control center section on close

* Drop session-item left border indicator

Remove the left-border accent used for active, CLI, and project rows —
each state already has a dedicated cue (gold fill, cli badge, project
dot), so the border was redundant. Fully round the row, add 2px
bottom spacing between rows, and strip the matching JS/CSS overrides.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Increase session search input vertical padding

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Normalise odd pixel values across UI

Snap padding, gap, and border-radius values to the 2/4/6/8/10/12 grid
across composer chips, sidebar panels, cron list, settings, approval
buttons, dropdowns, and inline message edit — eliminating the 7/9/11px
drift that was making sibling elements feel subtly misaligned.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Add missing #btnMobileFiles button and .mobile-files-btn CSS (for mobile QA suite)

The mobile layout regression suite (test_mobile_layout.py) requires:
- #btnMobileFiles onclick=toggleMobileFiles() in topbar chips
- .mobile-files-btn CSS rules for responsive show/hide at 640/900px breakpoints

Also adds max-width guard to .profile-dropdown to prevent clipping at narrow viewports.

* Improve composer footer mobile responsiveness and UX

- Collapse composer chips to icon-only at <=400px viewports
- Add model chip icon (CPU) so it remains tappable when labels are hidden
- Show send button always (disabled state when empty, hidden during streaming)
- Show context usage indicator on session load, not just after streaming
- Add cancel status fallback timeout to prevent stale "Cancelling..." text
- Update tests to match new send button and busy state behavior

* Fix duplicate files button and broken workspace close on mobile

Remove redundant #btnMobileFiles button that duplicated #btnWorkspacePanelToggle
in the mobile topbar. Fix workspace panel close button calling undefined
closeMobileFiles() — now calls closeWorkspacePanel().

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fix model chip icon vertical alignment in composer footer

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fix workspace toggle button hidden on desktop by conflicting CSS class

Remove mobile-files-btn class from #btnWorkspacePanelToggle — its
display:none!important rule was overriding workspace-toggle-btn visibility
on non-mobile viewports.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fix session actions dots button inaccessible on mobile sidebar

Always show the session actions trigger on mobile (no hover state on
touch devices) and restore right padding so text truncates with
ellipsis before the dots icon.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fix composer footer manage links not opening sidebar panel

The "Manage profiles" and "Manage workspaces" links in the composer
footer dropdowns called switchPanel() which only changes the active
panel content but doesn't open the sidebar. Replaced with
mobileSwitchPanel() which also opens the sidebar so the panel is
actually visible.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Widen icon-only composer chips breakpoint from 400px to 768px

Move the icon-only chip styling up into the existing max-width:768px
media query so chips collapse to icon-only on tablets too, preventing
composer footer overflow on mid-size screens.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fix composer-left vertical scrollbar by setting overflow-y:hidden

When overflow-x is set to auto, the CSS spec implicitly changes
overflow-y from visible to auto, allowing a vertical scrollbar to
appear from slight chip padding/border overflow. Explicitly set
overflow-y:hidden to prevent this.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: resolve rebase conflicts and fix control center test assertions

- Resolved 4 conflicts during rebase onto master (workspace.js,
  boot.js, index.html, test_sprint34.py)
- Fixed test_sprint34.py: _controlSection -> _settingsSection,
  cc-tab -> settings-tabs (matching actual implementation)
- Fixed quoting syntax error in test assertion

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: update version badge in System tab to v0.49.4

* docs: update README and CHANGELOG for v0.50.0 UI refresh, bump version badge

---------

Co-authored-by: Aron Prins <pwf.aron@gmail.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: Nathan Esquenazi <nesquena@gmail.com>

tests/test_regressions.py

@@ -226,8 +226,8 @@ def test_loadSession_resets_busy_state_for_idle_session(cleanup_test_sessions):
     src = (REPO_ROOT / "static/sessions.js").read_text()
     # The fix adds explicit S.busy=false in the non-inflight else branch
     assert "S.busy=false;" in src,         "sessions.js loadSession must set S.busy=false when loading a non-inflight session"
-    # btnSend must be explicitly re-enabled
-    assert "$('btnSend').disabled=false;" in src,         "sessions.js loadSession must enable btnSend for non-inflight sessions"
+    # btnSend state must be refreshed via updateSendBtn
+    assert "updateSendBtn()" in src,         "sessions.js loadSession must call updateSendBtn for non-inflight sessions"
 
 
 def test_done_handler_guards_setbusy_with_inflight_check(cleanup_test_sessions):
@@ -352,12 +352,12 @@ def test_respond_approval_uses_approval_session_id(cleanup_test_sessions):
     assert "_approvalSessionId" in fn_body,         "respondApproval must read _approvalSessionId, not S.session.session_id"
 
 
-# ── R11: Activity bar shows cross-session tool status ─────────────────────
+# ── R11: Tool progress must not use shared status chrome ──────────────────
 
 def test_tool_status_only_shown_for_current_session(cleanup_test_sessions):
-    """R11: The activity bar setStatus() call in the tool SSE handler must only
-    fire when the user is viewing the session that triggered the tool.
-    When missing, session A's tool names would appear in session B's activity bar.
+    """R11: Tool progress should not drive the global status bar or composer
+    status. Live tool cards in the current conversation are the authoritative
+    progress UI, which avoids cross-session status leakage entirely.
     """
     src = (REPO_ROOT / "static/messages.js").read_text()
     # Sprint 12: handler moved into _wireSSE(source)
@@ -366,14 +366,10 @@ def test_tool_status_only_shown_for_current_session(cleanup_test_sessions):
         tool_idx = src.find("es.addEventListener('tool'")
     assert tool_idx >= 0
     tool_block = src[tool_idx:tool_idx+400]
-    # setStatus must be inside the activeSid guard, not before it
-    status_pos = tool_block.find("setStatus(")
-    guard_pos  = tool_block.find("S.session.session_id===activeSid")
-    assert guard_pos >= 0, "tool handler must guard with activeSid check"
-    # The guard must appear BEFORE or AROUND the setStatus call
-    # (status only fires for the current session)
-    assert status_pos > tool_block.find("activeSid"), \
-        "setStatus in tool handler must be inside the activeSid guard"
+    assert "setStatus(" not in tool_block, \
+        "tool handler should not use the global activity/status bar"
+    assert "setComposerStatus(" not in tool_block, \
+        "tool handler should not use composer status for tool progress"
 
 # ── R12: Live tool cards lost on switch-away and switch-back ──────────────