permission-mode control beside the Claude composer (T-275)

Build the T-275 picker on the new popover primitive (D-88): an icon-only,
per-mode-coloured button trailing the composer text box opens a ClideMenu of
the safe trio (default/acceptEdits/plan, active marked) plus a divided, disabled
bypass row (the footgun stays behind the cockpit guard, T-181). The label lives
in the tooltip, the menu, and the status bar — the resting button is the glyph
alone. Coexists with the composer's Stop row when busy.

- new permission_mode_control.dart (PermissionModeControl + per-mode
  icon/colour helpers); shieldCheck/shieldWarning glyphs added to PhosphorIcons.
- claude_composer.dart: permissionMode + onSetPermissionMode props; control
  trails the text box (bottom-aligned), shown only when wired.
- claude_pane.dart: pass the current mode + a setter; demote the status-bar
  _ModeBadge to a passive, per-mode-coloured text indicator (no click). Ctrl/Cmd+M
  still cycles (onCycleMode unchanged).

Regenerated the phosphor-glyphs reference (47 defined). Tests: menu opens with
the trio + disabled bypass, select sets the mode, helpers map colours/icons,
control coexists with Stop, hidden when no mode.

Note: claude_pane.dart also carries the earlier T-274 resume diagnostic log line
(uncommitted in the working tree, reviewed as benign) — it rides along here.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/widgets/src/icons/phosphor.dart

@@ -53,6 +53,8 @@ abstract class PhosphorIcons {
   static const palette = PhosphorIconPainter(0xe6c8);
   static const warning = PhosphorIconPainter(0xe4e0);
   static const warningCircle = PhosphorIconPainter(0xe4e2);
+  static const shieldCheck = PhosphorIconPainter(0xe40c);
+  static const shieldWarning = PhosphorIconPainter(0xe412);
   static const check = PhosphorIconPainter(0xe182);
   static const checkCircle = PhosphorIconPainter(0xe184);
   static const caretLeft = PhosphorIconPainter(0xe138);