Change 2 — Add "desktop" DeviceType

DRAFT. Conforms to _GROUND-TRUTH.md.

VERDICT: already done. This change is a NO-OP against current source.

The brief assumed "desktop" was missing from DeviceType and that the type "likely" lives in src/shared/types.ts. Both assumptions are wrong against the ground-truth source:

1. DeviceType is defined in src/shared/sync-types.ts:11, not types.ts (types.ts has no DeviceType symbol). chirp-handshake.ts:29 and paired-devices.ts:23 both import device types from ./sync-types.

2. "desktop" is already a member:

   // src/shared/sync-types.ts:11
   export type DeviceType = "extension" | "android" | "ios" | "desktop";
   

3. The full desktop plumbing already exists:

   • DEVICE_TYPE_DESKTOP = 0x04 chirp byte tag (sync-types.ts:19)
   • DeviceTypeByte includes it (sync-types.ts:25)
   • deviceTypeFromByte(0x04) → "desktop" (sync-types.ts:36)
   • deviceTypeToByte("desktop") → 0x04 (sync-types.ts:45)
   • chirp-payload.ts accepts byte 0x04 on the wire (chirp-payload.ts:5,89)

4. peach-sync announces exactly this string: .device_type = "desktop" (peach-sync/src/pairing.zig:177), which lands on the existing union member.

No edit to the type union is required. If a downstream pass "adds" it again it will be a redundant no-op.

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What ACTUALLY needs verifying: the storage gate (paired-devices.ts)

The real question is whether the paired-device registry rejects a "desktop" device. It does not — there is no enum gate.

upsertPairedDevice (src/background/paired-devices.ts:56-70) validates only presence, never membership against the DeviceType union:

// paired-devices.ts:60
if (!device.deviceType) throw new Error("device.deviceType is required");

It checks the field is truthy, not that it equals a known literal. "desktop" (or any non-empty string) passes. Storage round-trips it verbatim (isPairedDevice, paired-devices.ts:174-180, only checks deviceId is a non-empty string and pairedAt is a number — deviceType is not gated).

PairedDevice.deviceType is DeviceType | undefined (sync-types.ts:89), so "desktop" is statically valid; nothing to extend.

Conclusion / action for implementer

• No code change for Change 2. Optionally, add a regression test asserting a "desktop" device upserts and round-trips through paired-devices.ts (kept minimal; the registry already supports it).
• If the brief's reviewer insists on a literal "edit", the only honest one is a doc/comment — there is no missing union member and no gate to widen.

Discrepancy summary (for the report)

• Brief said: add "desktop" to DeviceType in src/shared/types.ts.
• Source truth: "desktop" already present in src/shared/sync-types.ts:11; types.ts is the wrong file; the storage layer already accepts it. Change is unnecessary.