Add triggershell run/scripts - execute configured scripts from the CLI

`run <scriptId>` auto-detects whether the web server is already
reachable (a quick /api/healthz check):

- If it is, the run goes through the existing POST
  /api/scripts/:id/runs endpoint (token-authenticated, same as any
  other API client) and the CLI subscribes over /ws/runs exactly like
  a browser tab - so the run shows up live in Run History and any open
  browser watching it, with zero server-side changes, since the
  broadcast path has no idea a run was triggered by a click vs a CLI
  invocation.
- If nothing's reachable, it calls startRun() directly in its own
  process (after its own migrateOnBoot/reconcileOrphanedRuns, so a
  from-scratch .triggershell/ works standalone) and streams output by
  listening on the same in-process runEvents emitter a WS client would
  otherwise be fed from - read-log-then-listen, the same ordering
  ws/server.ts's subscribe() already uses, so a fast script finishing
  before the listener attaches still gets its output printed.

Both modes support --var name=value (repeatable; repeat a name for
multiselect), --no-wait, and Ctrl-C cancellation through the same
mechanism the web UI's Cancel button uses (a WS cancel message
remotely, cancelRun() directly locally). `scripts list`/`scripts show`
are local-only, no network - same direct-config-read pattern as
`validate`/`doctor`.

Extracts defaultValuesForScript() out of dynamic-form.tsx into
src/lib/config/defaults.ts so the CLI's --var handling and the web
form fill in a script's configured defaults identically instead of
duplicating that logic.

Verified live end-to-end: a CLI-triggered remote run was observed
streaming to both the triggering CLI process and an independent WS
client (simulating a browser tab) simultaneously; local-mode Ctrl-C
confirmed to actually kill the spawned child process, not just the
CLI; token, wrong-token, and TRIGGERSHELL_API_TOKEN auth paths all
verified against a running auth-enabled server.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/cli/lib/network.ts

@@ -36,6 +36,19 @@ export async function waitUntilReady(
   return false;
 }
 
+/** Single-shot check (not a poll loop, unlike `waitUntilReady`) for whether a triggershell server
+ * is already listening at `url` - used to decide whether `run` can go through the REST/WS API. */
+export async function isServerReachable(url: string): Promise<boolean> {
+  try {
+    const response = await fetch(`${url}/api/healthz`, {
+      signal: AbortSignal.timeout(1000),
+    });
+    return response.status === 200;
+  } catch {
+    return false;
+  }
+}
+
 export function openBrowser(url: string): void {
   const command =
     process.platform === "darwin" ? "open" : process.platform === "win32" ? "start" : "xdg-open";