fix: stream bash output and harden OpenCode connectivity (#2522)

* fix(ui): stream bash tool output while running

* perf(ui): render streaming bash output incrementally

* fix(ui): keep tool duration timer running

* fix(web): recover stalled OpenCode SSE streams

* fix(web): prevent OpenCode restart storms

* fix: address streaming recovery review

packages/ui/src/components/chat/message/parts/ToolPart.test.ts

@@ -2,6 +2,46 @@ import { describe, expect, test } from 'bun:test';
 
 import { readTaskTagSessionIdFromOutput } from './taskSessionIdParser';
 import { tryParseJsonOutput } from '../toolRenderers';
+import { getStreamingThrottleText } from '../../hooks/useStreamingTextThrottle';
+import { getStreamingOutputAppend, getToolOutput } from './toolOutput';
+
+describe('getToolOutput', () => {
+    test('prefers authoritative state output', () => {
+        expect(getToolOutput('bash', 'final output', 'streamed output')).toBe('final output');
+        expect(getToolOutput('bash', '', 'streamed output')).toBe('');
+    });
+
+    test('falls back to streamed metadata output for bash', () => {
+        expect(getToolOutput('bash', undefined, 'streamed output')).toBe('streamed output');
+        expect(getToolOutput('bash', undefined, '')).toBe(undefined);
+    });
+
+    test('does not expose metadata output for other tools', () => {
+        expect(getToolOutput('read', undefined, 'metadata output')).toBe(undefined);
+    });
+});
+
+describe('getStreamingOutputAppend', () => {
+    test('returns only newly appended output', () => {
+        expect(getStreamingOutputAppend('first\n', 'first\nsecond\n')).toBe('second\n');
+    });
+
+    test('requires replacement when output is rewritten or shortened', () => {
+        expect(getStreamingOutputAppend('progress 10%', 'progress 20%')).toBe(undefined);
+        expect(getStreamingOutputAppend('long output', 'short')).toBe(undefined);
+    });
+});
+
+describe('streaming output transitions', () => {
+    test('allows bash snapshots to be rewritten or shortened while running', () => {
+        expect(getStreamingThrottleText('progress 10%', 'progress 20%', true, true)).toBe('progress 20%');
+        expect(getStreamingThrottleText('long output', 'short', true, true)).toBe('short');
+    });
+
+    test('preserves monotonic streaming text by default', () => {
+        expect(getStreamingThrottleText('long output', 'short', true, false)).toBe('long output');
+    });
+});
 
 describe('readTaskTagSessionIdFromOutput', () => {
     test('parses task tags without state attributes', () => {