fix(runtime): join the resize repaint's seed without per-PTY seed state

Replaces the rendererSeedsByPtyId map with a check over existing state. If
an on-data seed was already considered before the subscribe's hydrate, the
subscribe awaits the model's write chain and reads the outcome from the
hydration state, the installed model and the provider-preferred flag.

Claude-Session: lane-host-hydrate

src/main/runtime/orca-runtime-fit-override-listeners.ts

@@ -130,8 +130,6 @@ export class OrcaRuntimeWithFitOverrideListeners extends OrcaRuntimeWithStopRequ
   // Absent  → hydration has not been considered yet for this PTY.
   // See docs/mobile-prefer-renderer-scrollback.md.
   protected headlessHydrationState = new Map<string, 'pending' | 'done'>()
-  /** The model's renderer seed, resolving true once written; lives as long as the model. */
-  protected rendererSeedsByPtyId = new Map<string, Promise<boolean>>()
 
   // Why: mobile-fit overrides are keyed by ptyId (not terminal handle) because
   // handles can be reissued while the PTY identity is stable. In-memory only —

src/main/runtime/orca-runtime-maybe-hydrate-headless-from-renderer.ts

@@ -110,19 +110,32 @@ export class OrcaRuntimeWithMaybeHydrateHeadlessFromRenderer extends OrcaRuntime
         }
       }
     })
-    const seed = state.writeChain.then(() => seeded)
-    this.rendererSeedsByPtyId.set(ptyId, seed)
-    return seed
+    return state.writeChain.then(() => seeded)
   }
 
   /** Public: a phone fit resizes the PTY, but an idle TUI sends no byte to hydrate on. Resolves
    *  true once the model holds the pane's screen reflowed onto the PTY's current grid. */
   hydrateHeadlessTerminalFromRenderer(ptyId: string): Promise<boolean> {
-    // Why join: a resize repaint can run the on-data seed first; its result answers this caller too.
+    const priorHydration = this.headlessHydrationState.get(ptyId)
+    const seed = this.maybeHydrateHeadlessFromRenderer(ptyId)
+    if (seed) {
+      return seed
+    }
+    // Why: a resize repaint can run the on-data seed before this call; join its outcome instead.
+    return priorHydration ? this.readRendererSeedOutcome(ptyId) : Promise.resolve(false)
+  }
+
+  private async readRendererSeedOutcome(ptyId: string): Promise<boolean> {
+    const state = this.headlessTerminals.get(ptyId)
+    if (!state) {
+      return false
+    }
+    await state.writeChain
+    // Why: a failed seed also ends 'done'; treated as seeded, since that model is on the PTY grid.
     return (
-      this.maybeHydrateHeadlessFromRenderer(ptyId) ??
-      this.rendererSeedsByPtyId.get(ptyId) ??
-      Promise.resolve(false)
+      this.headlessHydrationState.get(ptyId) === 'done' &&
+      this.headlessTerminals.get(ptyId) === state &&
+      !this.providerSnapshotPreferredPtys.has(ptyId)
     )
   }
 

src/main/runtime/orca-runtime-serialize-headless-terminal-buffer.ts

@@ -75,7 +75,6 @@ export class OrcaRuntimeWithSerializeHeadlessTerminalBuffer extends OrcaRuntimeW
 
   protected disposeHeadlessTerminal(ptyId: string): void {
     this.headlessHydrationState.delete(ptyId)
-    this.rendererSeedsByPtyId.delete(ptyId)
     const state = this.headlessTerminals.get(ptyId)
     if (!state) {
       return

src/main/runtime/pty-exit-per-pty-map-reaper-ratchet.test.ts

@@ -41,10 +41,6 @@ const CLEARED_BY_REAPER_HELPER: Record<string, { helper: string; module: string
   agentPromptPermissionSequenceByPtyId: {
     helper: 'advancePtyLifecycleGeneration',
     module: 'src/main/runtime/orca-runtime-record-agent-prompt-lifecycle-state.ts'
-  },
-  rendererSeedsByPtyId: {
-    helper: 'disposeHeadlessTerminal',
-    module: 'src/main/runtime/orca-runtime-serialize-headless-terminal-buffer.ts'
   }
 }