finish phase 0 of the opencode parity list

Three defects and one honest removal. Each was reproduced before being changed, as the doc asks.

B4 — images were offered and silently discarded. Every OpenCode model advertised `images: true`, the
composer gates on that flag, the bubble rendered the attachment, and `handleOpenCodeChat`'s message type
has no `images` field, so it never left officer. Flipped to false: 61 OpenCode models now decline, the
three Claude ones still accept. Plumbing them through OpenCodeRunParams stays Phase 4; advertising a
capability that does not exist is the part worth fixing today.

B5 — every OpenCode turn overwrote the previous turn's subscription handle without detaching it, so the
old session-scoped listener stayed attached and delivery doubled, tripled, and so on for any termination
that is not result/error/stopped. Deliberately NOT the Claude guard: Claude keeps one persistent session
and skips re-subscribing, while OpenCode spawns a fresh `opencode run` per turn, so a new subscription
each time is correct — detaching the old one is what was missing.

B6 — the sessionKey → `ses_…` map had no writer of deletions, so it grew for the process lifetime and a
reused key resumed a stale OpenCode session. Cleared in `deleteSession` only, never in `releaseSession`:
releasing means "let go, leave it running", and a returning browser must find the same `ses_…` again.

Phase 0 item 1 — the thinking toggle is removed rather than fixed. `thinking` is accepted on the wire
and forwarded by neither channel, so the control changed its own label and nothing else. Out of scope
for both harnesses by decision. The inert plumbing beneath it is left for a follow-up that touches the
socket contract; the props stay accepted-and-unread so no call site had to change.

Phase 0 is complete: B1, B2, B3 landed earlier; B4, B5, B6 and the selector here.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/workspaces/officerdev/src/apps/Chat/components/ModelSelector.tsx

@@ -31,8 +31,13 @@ type ModelSelectorProps = {
   isConnected: boolean;
   isGenerating: boolean;
   hasStarted: boolean;
-  thinkingLevel: string | null;
-  onThinkingChange: (level: string | null) => void;
+  /**
+   * Still accepted so no call site has to change, and deliberately unread: the control they drove was
+   * removed because nothing forwarded `thinking` to either harness. Delete both when the rest of the
+   * plumbing goes.
+   */
+  thinkingLevel?: string | null;
+  onThinkingChange?: (level: string | null) => void;
 };
 
 export function ModelSelector({
@@ -44,8 +49,6 @@ export function ModelSelector({
   isConnected,
   isGenerating,
   hasStarted,
-  thinkingLevel,
-  onThinkingChange,
 }: ModelSelectorProps) {
   const providers = [...new Set(availableModels.map((m) => m.provider).filter(Boolean))] as string[];
 
@@ -117,14 +120,16 @@ export function ModelSelector({
           ))}
         </div>
       )}
+      {/* The thinking toggle used to render here. It is gone because it did nothing: `thinking` is
+          accepted on the wire (types.ts, websocket.ts) and forwarded by NEITHER channel — not
+          send-claude-code.ts, not send-opencode.ts — so pressing it changed the label and nothing else.
+          A control that lies is worse than an absent one.
+
+          Out of scope for both harnesses by decision (parity doc, 2026-08-10), so this is a removal
+          rather than a stopgap. The plumbing under it (`thinkingLevel` through useChat /
+          useEmbeddableChat, `ThinkingLevel` in types.ts) is still threaded and still inert; deleting it
+          is a separate change that touches the socket contract. */}
       <div className="flex min-w-0 shrink-0 items-center gap-2">
-        {availableModels.find((m) => m.id === displayModel)?.reasoning && (
-          <ThinkingToggle
-            enabled={thinkingLevel === 'high'}
-            onToggle={() => onThinkingChange(thinkingLevel === 'high' ? 'off' : 'high')}
-            disabled={isGenerating}
-          />
-        )}
         <div className="min-w-0 text-xs text-muted-foreground">
           {providerModels.length > 0 ? (
             <Select
@@ -151,25 +156,3 @@ export function ModelSelector({
     </div>
   );
 }
-
-// ── Thinking Toggle ──
-
-type ThinkingToggleProps = {
-  enabled: boolean;
-  onToggle: () => void;
-  disabled: boolean;
-};
-
-const ThinkingToggle = ({ enabled, onToggle, disabled }: ThinkingToggleProps) => (
-  <button
-    type="button"
-    onClick={onToggle}
-    disabled={disabled}
-    title={enabled ? 'Thinking enabled (click to disable)' : 'Thinking disabled (click to enable)'}
-    className={`shrink-0 rounded-md px-2 py-0.5 text-xs font-medium transition-colors cursor-pointer disabled:cursor-not-allowed disabled:opacity-40 ${
-      enabled ? 'bg-info/15 text-info' : 'text-muted-foreground hover:text-foreground'
-    }`}
-  >
-    {enabled ? 'think' : 'no think'}
-  </button>
-);