icons from extensions, settings-based tab ordering, static context tabs

Icons now declared on TabContribution via the icon field — the
hardcoded switch in _BottomRail is a fallback only. All sidebar
and context extensions set their Phosphor icon explicitly.

PanelRegistry supports setTabOrder(slot, List<String>) — tabs
render in the order specified by project.layout.sidebar.order /
context.order in settings.yaml. Falls back to registration order.
Priority field removed from all contributions.

Context tabs are static again — persist with their last content,
selection just loads new data and switches focus. No spawn/despawn.

Tickets sidebar priority set to -200 (leftmost, default open).

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

lib/builtin/decisions/src/extension.dart

@@ -1,11 +1,8 @@
-import 'dart:async';
-
 import 'package:clide/builtin/decisions/src/decision_detail_view.dart';
 import 'package:clide/builtin/decisions/src/decisions_view.dart';
 import 'package:clide/extension/extension.dart';
 import 'package:clide/kernel/kernel.dart';
-import 'package:clide/kernel/src/events/message_bus.dart';
-import 'package:flutter/foundation.dart' show VoidCallback;
+import 'package:clide/widgets/widgets.dart';
 
 class DecisionsExtension extends ClideExtension {
   @override
@@ -13,15 +10,10 @@ class DecisionsExtension extends ClideExtension {
   @override
   String get title => 'Decisions';
   @override
-  String get version => '0.3.0';
+  String get version => '0.5.0';
   @override
   List<String> get dependsOn => const [];
 
-  ClideExtensionContext? _ctx;
-  StreamSubscription<Message>? _selectionSub;
-  VoidCallback? _panelListener;
-  bool _detailSpawned = false;
-
   @override
   List<ContributionPoint> get contributions => [
         TabContribution(
@@ -30,54 +22,15 @@ class DecisionsExtension extends ClideExtension {
           title: 'Decisions',
           titleKey: 'tab.title',
           i18nNamespace: id,
-          priority: -20,
+          icon: PhosphorIcons.lightbulb,
           build: (_) => const DecisionsView(),
         ),
+        TabContribution(
+          id: 'decisions.detail',
+          slot: Slots.contextPanel,
+          title: 'Decision',
+          icon: PhosphorIcons.lightbulb,
+          build: (_) => const DecisionDetailView(),
+        ),
       ];
-
-  @override
-  Future<void> activate(ClideExtensionContext ctx) async {
-    _ctx = ctx;
-    _selectionSub = ctx.messages.subscribe(publisher: id, channel: 'selection').listen(_onSelection);
-    _panelListener = () {
-      if (_detailSpawned && ctx.panels.activeTabIn(Slots.contextPanel) != 'decisions.detail') {
-        _despawnDetail();
-      }
-    };
-    ctx.panels.addListener(_panelListener!);
-  }
-
-  @override
-  Future<void> deactivate() async {
-    _selectionSub?.cancel();
-    if (_panelListener != null) _ctx?.panels.removeListener(_panelListener!);
-    _despawnDetail();
-  }
-
-  void _onSelection(Message msg) {
-    final ctx = _ctx;
-    if (ctx == null) return;
-    final selectedId = msg.data['id'] as String?;
-    if (selectedId == null) return;
-
-    if (_detailSpawned) {
-      _despawnDetail();
-    }
-    ctx.panels.contribute(TabContribution(
-      id: 'decisions.detail',
-      slot: Slots.contextPanel,
-      title: 'Decision',
-      priority: -50,
-      build: (_) => DecisionDetailView(initialId: selectedId),
-    ));
-    _detailSpawned = true;
-    ctx.panels.activateTab(Slots.contextPanel, 'decisions.detail');
-  }
-
-  void _despawnDetail() {
-    if (_detailSpawned) {
-      _ctx?.panels.uncontribute('decisions.detail');
-      _detailSpawned = false;
-    }
-  }
 }