fix(cassettes): publish state on every change, and make the stamps monotonic

Three linked failures in one mechanism, so one commit.

The state publish was gated on a one-shot 'have we said hello' flag. It
fired once on first boot and then only after a dispense or an applied
operator config, so any change to the layout itself — a reseed, an
atm-tui edit, direct SQL — was never announced. The operator kept
validating against a bay set the machine no longer had, and a publish
from the dashboard could overwrite a fresh seed (#94). State is now
published on every start.

A publish is one fire-and-forget event with no retry. If the relay was
unreachable at the moment of a dispense, that update was gone until the
next customer bought cash. A five-minute heartbeat makes the channel
self-healing and is also the only way an out-of-band edit to the table
ever reaches the operator.

Addressable events are ordered by created_at at second granularity with
ties broken by lowest event id, and a relay acknowledges an event it
then discards. Two publishes inside one second therefore left the winner
decided by a hash, permanently, and a clock stepping backwards would
have made every report from this machine vanish silently. Each publish
now takes a stamp strictly above the last, recorded in the meta row that
used to hold the gate — same key, no migration, honest name.

Closes #94

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

apps/machine/electron/preload.ts

@@ -108,16 +108,16 @@ contextBridge.exposeInMainWorld('electronAPI', {
   // Operator-config consumer (aiolabs/lamassu-next#56)
   getLastKnownConfigCreatedAt: (): Promise<number> =>
     ipcRenderer.invoke('state:get-last-known-config-created-at'),
-  getBootstrapPublishedAt: (): Promise<number | null> =>
-    ipcRenderer.invoke('state:get-bootstrap-published-at'),
-  markBootstrapPublished: (unixTimestamp: number): Promise<void> =>
-    ipcRenderer.invoke('state:mark-bootstrap-published', unixTimestamp),
+  getLastStatePublishedAt: (): Promise<number | null> =>
+    ipcRenderer.invoke('state:get-last-state-published-at'),
+  markStatePublished: (unixTimestamp: number): Promise<void> =>
+    ipcRenderer.invoke('state:mark-state-published', unixTimestamp),
 
   // Bunker binding persistence (aiolabs/bitspire#52)
   saveBunkerBinding: (binding: BunkerBindingRecord): Promise<void> =>
     ipcRenderer.invoke('state:save-bunker-binding', binding),
   clearBunkerBinding: (): Promise<void> => ipcRenderer.invoke('state:clear-bunker-binding'),
-  resetBootstrapGate: (): Promise<void> => ipcRenderer.invoke('state:reset-bootstrap-gate'),
+  resetStatePublishWatermark: (): Promise<void> => ipcRenderer.invoke('state:reset-state-publish-watermark'),
   resetForRepair: (): Promise<void> => ipcRenderer.invoke('state:reset-for-repair'),
 
   // QR-pairing wizard (aiolabs/bitspire#52): persist a scanned spire-seed,
@@ -289,11 +289,11 @@ declare global {
       emptyCashbox: () => Promise<void>
       remediateTransaction: (txid: string, remediatedByTxid: string) => Promise<boolean>
       getLastKnownConfigCreatedAt: () => Promise<number>
-      getBootstrapPublishedAt: () => Promise<number | null>
-      markBootstrapPublished: (unixTimestamp: number) => Promise<void>
+      getLastStatePublishedAt: () => Promise<number | null>
+      markStatePublished: (unixTimestamp: number) => Promise<void>
       saveBunkerBinding: (binding: BunkerBindingRecord) => Promise<void>
       clearBunkerBinding: () => Promise<void>
-      resetBootstrapGate: () => Promise<void>
+      resetStatePublishWatermark: () => Promise<void>
       resetForRepair: () => Promise<void>
       saveSpireSeed: (seed: string) => Promise<void>
       relaunchApp: () => Promise<void>