🐛 Fix CLI regressions across JSON, help, and TDD

Running the real CLI exposed failures at the boundaries users actually consume: command routing showed misleading help, JSON mode could leak human text to stdout, TDD lifecycle commands were unsafe around explicit ports, preview/upload errors were hidden behind auth, and status could fail on optional preview metadata from the API.

Covered and fixed:

- Command routing and help: unknown root/nested commands now fail with the right recovery hints, root help categorizes built-ins correctly, TDD help shows full command paths, documents lifecycle --port flags, and hides internal --daemon-child.

- JSON contracts: command validation, commander errors, TDD commands, noisy child processes, run --json --wait, and status --json now keep stdout machine-readable and move child/user noise to stderr.

- TDD daemon lifecycle: start/status/stop/list now respect explicit ports, isolated VIZZLY_HOME state, stale daemon files, registry-backed daemons, and wrong-port no-ops without killing or cleaning unrelated processes.

- TDD/run UX: one-shot runs suppress human summaries in JSON mode, avoid pointing build-backed static runs at a live dashboard, and preserve the static report path users need after local review.

- Preview/upload/config/review/status CLI paths: preview and upload validate local paths before auth, config and review have real CLI coverage, upload rejects missing or non-directory inputs clearly, and status returns preview: null when the API has no preview metadata.

- Test coverage: added CLI-boundary tests that run the actual command entrypoint against local workspaces and local HTTP API servers instead of mocking internal modules.

Author: Robdel12

README.md

@@ -40,11 +40,13 @@ Use `vizzly init --agent-skill` to install only the local skill, or
 
 ### Start Local TDD
 
-Start the TDD server, run your tests, and open the dashboard at
-`http://localhost:47392`.
+Start the TDD server, run your tests, and open the dashboard at the URL the
+command prints. Add `--open` when you want Vizzly to open the dashboard for
+you. If the default port is busy, Vizzly picks the next available port; use the
+printed `--port` value with `vizzly tdd status` or `vizzly tdd stop`.
 
 ```bash
-vizzly tdd start
+vizzly tdd start --open
 pnpm test -- --watch
 ```
 
@@ -206,7 +208,10 @@ export default {
 | Command | What it does |
 | --- | --- |
 | `vizzly tdd start` | Start the local TDD server and dashboard. |
-| `vizzly tdd run "cmd"` | Run tests once and generate a static visual report. |
+| `vizzly tdd status` | Check the local TDD server for this project. |
+| `vizzly tdd list` | List running local TDD servers. |
+| `vizzly tdd stop` | Stop the local TDD server for this project. |
+| `vizzly tdd run "cmd"` | Run tests once, generate a static visual report, and open it by default. |
 | `vizzly run "cmd"` | Run tests with cloud build and review integration. |
 | `vizzly context ...` | Fetch visual context for builds, comparisons, screenshots, and review queues. |
 | `vizzly upload <dir>` | Upload an existing folder of screenshots. |