fix(web-ui): cwd-relative path summaries, sweep glare rework, uniform 16px chat rhythm

Tool row summaries strip the session workspace root; the running sweep
becomes a glare-band overlay (deepsuite ShimmerText pattern); assistant
nodes that render nothing no longer split tool-row groups; block and
tool-row spacing collapse to one 16px rhythm.

packages/client/ui-conversation/tests/chat-tool-row.spec.tsx

@@ -64,6 +64,16 @@ describe('tool-call-model', () => {
     expect(toolRowModel('', running({ argsRaw: '' })).summary).toBe('c1')
   })
 
+  it('displays workspace-rooted paths relative to the session cwd', () => {
+    const cwd = '/Users/u/ws/'
+    expect(toolRowModel('edit', running({ name: 'edit', argsRaw: '{"file_path":"/Users/u/ws/src/x.ts"}' }), cwd).summary).toBe('src/x.ts')
+    expect(toolRowModel('read', running({ name: 'read', argsRaw: '{"path":"/Users/u/ws/a.md"}' }), cwd).summary).toBe('a.md')
+    // Paths outside the workspace (and non-path summaries) stay verbatim.
+    expect(toolRowModel('read', running({ name: 'read', argsRaw: '{"path":"/etc/hosts"}' }), cwd).summary).toBe('/etc/hosts')
+    expect(toolRowModel('bash', running({ argsRaw: '{"command":"pwd"}' }), cwd).summary).toBe('pwd')
+    expect(toolRowModel('read', running({ name: 'read', argsRaw: '{"path":"/Users/u/ws/a.md"}' }), '').summary).toBe('/Users/u/ws/a.md')
+  })
+
   it('body pretty-prints JSON args, keeps raw non-JSON, null when empty', () => {
     expect(toolRowModel('bash', running({ argsRaw: '{"a":1}' })).body).toBe('{\n  "a": 1\n}')
     expect(toolRowModel('bash', running({ argsRaw: 'raw' })).body).toBe('raw')

packages/client/ui-conversation/tests/chat-view.spec.tsx

@@ -131,6 +131,21 @@ describe('chat-flow derivation', () => {
     expect(flowKeys(items)).toBe('n1|n2|g3|n5|g6')
     expect(flowKeys(deriveChatFlow([...nodes, toolResult(7, 'd')]))).toBe('n1|n2|g3|n5|g6')
   })
+
+  it('skips render-nothing assistant nodes so tool runs stay one group', () => {
+    // A tool-call-only step message (and blank text/reasoning) renders nothing:
+    // it must not split the run into two groups with an empty line between.
+    const headsOnly: AssistantMessageNode = {
+      kind: 'assistant', seq: 4, time: 4_000, turn: 1, step: 2,
+      blocks: [{ kind: 'tool-call', callId: 'b', name: 'read', argsRaw: '{}' }, { kind: 'text', text: ' \n' }, { kind: 'reasoning', text: '' }],
+    }
+    const items = deriveChatFlow([toolResult(3, 'a'), headsOnly, toolResult(5, 'b')])
+    expect(flowKeys(items)).toBe('g3')
+    expect(items[0]!.kind === 'tool-group' && items[0].results.map(r => r.callId)).toEqual(['a', 'b'])
+    // Interrupted and visible-content nodes still render (已停止 marker / prose).
+    expect(flowKeys(deriveChatFlow([toolResult(3, 'a'), { ...headsOnly, interrupted: true }, toolResult(5, 'b')]))).toBe('g3|n4|g5')
+    expect(flowKeys(deriveChatFlow([toolResult(3, 'a'), assistant(4, 'found'), toolResult(5, 'b')]))).toBe('g3|n4|g5')
+  })
 })
 
 describe('ChatView', () => {