feat(cli): wavegrid signals — send, probe and listen to OSC for debugging Pangolin

[pyramation]

Summary

Debugging "is BEYOND receiving anything?" and "which zone is fixture 7?" with a show that streams a whole grid at 30 Hz is hopeless. This adds three hand-driven OSC commands that aim at the project's configured target, so they exercise the same path — same encoders, same addresses — as the running show:

wavegrid signals send /beyond/zone/0/livecontrol/red 255   # one message, one time
wavegrid signals probe --zones 0-11 --hold 500             # light one zone at a time, then blackout
wavegrid signals listen --port 7001                        # print every message arriving on a port

listen is the piece that makes the rest verifiable: UDP gives no delivery signal, so pointing the show at --host 127.0.0.1 --port <n> and listening there is how you see the exact bytes the hardware would get (verified end-to-end locally — probe → listen shows the /beyond/zone/N/livecontrol/* frames and the closing blackout).

Two details worth knowing:

• Argument typing. Tokens are floats unless tagged, because an int where the receiver wants a float is dropped silently: 255 → f:255, i:3 → integer, s:text → string.
• The blackout frame must not be lost. adapter.close() on a UDP socket discards queued sends, so an early version's blackout never left the machine — the lit fixture would stay lit after the probe "finished". The probe now holds one adapter for the whole walk and waits FLUSH_MS after the final dark frame before closing.

New primitives live in @wavegrid/osc (sendOscMessage, listenForOsc, parseOscArg, parseIndexRange, probeGrid) so node-osc stays in one package; the CLI gains a @wavegrid/osc dependency.

Aiming precedence, with no guessing:

--host [--port] [--kind fb4]   →   project config BEYOND   →   project config FB4   →   error

This is deliberate output on a target the operator configured. It is unrelated to tools/traffic, which stays passive: nothing here replays captures or invents hardware commands, and probe prints a "lasers will output" warning and supports --dry-run.

Test plan

• packages/osc/__tests__/debug.test.ts — arg typing/tags, index-range expansion, one-lit-fixture grids, plus a real UDP round trip (sendOscMessage → listenForOsc) asserting the address and float survive.
• packages/cli/__tests__/osc-signals.test.ts — target resolution: config BEYOND, FB4 fallback, flags winning, port-only override, and the refusal when nothing is configured.
• Manual: signals send, then signals probe --zones 0-1 against signals listen on loopback; confirmed the blackout frame arrives (it did not before the flush fix).
• pnpm -r test, pnpm -r run lint, and CLI/OSC builds pass.

Link to Devin session: https://app.devin.ai/sessions/ec43152136134467a853ec0bbf783ea9
Requested by: @pyramation

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