feat(cli): claw run tails the server-side run in the terminal

[EdmondDantes]

What

The third slice of TODO item 2. #92 made claw run hand the run to the server and return; this brings the live view back to the terminal. After starting the run, the CLI follows it and prints the trace as it arrives, ending when the run does.

• Server: GET /api/projects/{key}/issues/{id}/runs — the runs for an issue (needed because the run id is minted inside the run, so a start cannot return it).
• ServerClient: runs(), trace(), latestRunId(), awaitRun() — find the run a start produced (the first id past the pre-start high-water mark) and poll its trace.
• WorkflowMode::tailRun() — renders each trace row exactly as an in-process run does (same TraceFormat, same depth indentation and ▶ ◀ · glyphs, same level threshold from -q/-v), and stops on done/failed.

Behaviour

• claw run prints the run's trace live again, then Run #N finished issue #M. (or a failure pointer to claw log).
• A human gate shows ⏸ waiting for a human — answer it in the dashboard; Ctrl-C detaches (the run continues). Detaching loses only the view — the run keeps going on the server and claw log shows the rest. Answering the gate from the terminal is the next slice (3b).
• If the CLI can't attach a tail (no run appears in time), it falls back to watch it with: claw log and exits 0.

Verified live

Against the real server extension: claw run 6 autospawned a server, started the run, discovered its id, and rendered the trace as it worked —

▶ workflow Issue6Solver
  ▶ step implementStatsClass
  ◀ end
  ▶ workflow supervise-run
    ▶ step repair
          · tool recall
          · tool-result recall  Title: Statistics module with tests…
          · tool list_files
          · tool read_file

Design notes

• Polling, not SSE. The trace poll (?since=<seq>) is the SSE fallback endpoint and returns the same rows; CurlHttpClient buffers the whole body, so it cannot stream an SSE response anyway. 500 ms cadence.
• List endpoints (runs, trace) are decoded directly in ServerClient, not via HttpResponse::json() — that method refuses a top-level JSON array by contract (it is for string-keyed objects). This surfaced as three tests throwing HttpException; Testo's parallel runner misattributed them to unrelated files at first.

Not in this PR

• 3b: answering the gate from the terminal (POST …/answer), which turns the read-only tail interactive.
• /start returning the run id (would remove the awaitRun discovery poll; deferred because the id is created mid-run).

Checks

composer qa green — cs, PHPStan level 8, Testo (457 tests). New ServerClient tests cover the run-list parsing, latestRunId, awaitRun, and trace decoding (incl. the top-level-array case).