fix(web-read-card): align highlight grammars with read hints, fix fixture schema, restore running sweep

Register the full grammar set the read tool's langFromPath emits (python,
go, rust, yaml, markdown, html, and the rest) so a read card highlights the
same extensions the backend recognizes instead of returning undefined for
them. Rewrite highlightLines' terminator-line check to the explicit
last !== undefined form to keep a single branch for per-file coverage.

Add the running-state sweep animation to ReadRow, matching BashRow/ToolRow,
so a running read row shows executing feedback.

Use file_path (the real read tool schema field) in the turn 66 read fixture
sample, its presentCall branch, and the turn 64 run_code read sub-dispatches,
so the built-boot snapshot replays a production-shaped call and the details
panel shows the correct Input JSON.

Document why ReadBlock omits TerminalBlock's empty-window copy guard, and
correct the read-card-model {@link} and the turn 66 fixture comment.

packages/client/connection/src/client/fixture.ts

@@ -267,8 +267,8 @@ function buildAlphaLog(): SessionEvent[] {
     const turn = 64
     const callId = `fx-call-${turn}`
     const program = 'const listing = await tools.bash({ command: "ls notes", description: "List notes" })\n'
-      + 'const demo = await tools.read({ path: "notes/demo.txt" })\n'
-      + 'await tools.read({ path: "notes/missing.txt" }).catch(() => "tolerated")\n'
+      + 'const demo = await tools.read({ file_path: "notes/demo.txt" })\n'
+      + 'await tools.read({ file_path: "notes/missing.txt" }).catch(() => "tolerated")\n'
       + 'return { listing, demo }'
     const args = JSON.stringify({ code: program, description: 'Read the notes files and summarize' })
     push({ type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } })
@@ -293,8 +293,8 @@ function buildAlphaLog(): SessionEvent[] {
       })
     }
     dispatchPair(1, 'bash', { command: 'ls notes', description: 'List notes' }, 'demo.txt\nnew-demo.txt')
-    dispatchPair(2, 'read', { path: 'notes/demo.txt' }, 'hello fixture\n')
-    dispatchPair(3, 'read', { path: 'notes/missing.txt' }, 'Error: ENOENT: notes/missing.txt not found', true)
+    dispatchPair(2, 'read', { file_path: 'notes/demo.txt' }, 'hello fixture\n')
+    dispatchPair(3, 'read', { file_path: 'notes/missing.txt' }, 'Error: ENOENT: notes/missing.txt not found', true)
     push({
       type: 'tool/result', surfaceOp: 'append',
       data: { turn, step: 0, message: toolResultMessage(callId, text('{"listing":"demo.txt\\nnew-demo.txt","demo":"hello fixture\\n"}'), false) },
@@ -326,13 +326,16 @@ function buildAlphaLog(): SessionEvent[] {
   // Turn 66: the read sample — a WINDOW past an offset so the card draws file
   // line numbers starting above 1 and a "showing N of M" note (the window is
   // shorter than READ_SAMPLE_TOTAL), with a `ts` language hint the shiki path
-  // highlights. Named `read`, so it exercises the keyed ReadRow registration
-  // (the render-site fallback row is covered by the read sub-dispatches in the
-  // turn 64 run_code sample). The read render intent is result-side only, so its
-  // pending call stays a generic `kind: 'read'` card; presentResult carries the
+  // highlights. Named `read`, so it exercises the keyed ReadRow registration.
+  // The render-site fallback ROW SHAPE (a read call on the generic flattened
+  // path) is covered by the turn 64 run_code read sub-dispatches, which
+  // session.ts folds with resultView: null; the fallback-row + read-CARD
+  // combination is pinned by the web_fetch case in read-card.spec.tsx, not by
+  // this fixture. The read render intent is result-side only, so its pending
+  // call stays a generic `kind: 'read'` card; presentResult carries the
   // structured window. Ordered BEFORE the todo turn for the same reason the
   // terminal sample is: the standing plan retires at the next `turn/start`.
-  toolTurn(66, 'read', `{"path":${JSON.stringify(READ_SAMPLE_PATH)},"offset":${READ_SAMPLE_FIRST_LINE}}`, READ_SAMPLE_TEXT)
+  toolTurn(66, 'read', `{"file_path":${JSON.stringify(READ_SAMPLE_PATH)},"offset":${READ_SAMPLE_FIRST_LINE}}`, READ_SAMPLE_TEXT)
 
   const todoArgs = JSON.stringify({ todos: fixtureTodos })
   toolTurn(67, 'todo_write', todoArgs, 'Updated todo list: 1 pending, 1 in progress, 1 completed.')
@@ -375,7 +378,7 @@ function presentCall(name: string, argsRaw: string): ToolCallView | undefined {
     // carries no file content until execute returns. The rich read card arrives
     // in presentResult.
     case 'read':
-      return { card: 'generic', title: `Read ${str(args.path)}`, kind: 'read', locations: [{ path: str(args.path) }] }
+      return { card: 'generic', title: `Read ${str(args.file_path)}`, kind: 'read', locations: [{ path: str(args.file_path) }] }
     case 'edit':
       return { card: 'generic', title: `Edit ${str(args.file_path)}`, kind: 'edit', rawInput: args }
     case 'write':