fix: resolve publish blockers for v3.7.4→v3.8.0 release

- Fix #1991 crash: optional chaining for task-history sessionID access
- Fix #1992 think-mode: add antigravity entries to HIGH_VARIANT_MAP
- Fix #1949 Copilot premium misattribution: use createInternalAgentTextPart
- Fix #1982 load_skills: pass directory to discoverSkills for project-level skills
- Fix command priority: sort scopePriority before .find(), project-first return
- Fix Google provider transform: apply in userFallbackModels path
- Fix ralph-loop TUI: optional chaining for event handler
- Fix runtime-fallback: unify dual fallback engines, remove HTTP 400 from retry,
  fix pendingFallbackModel stuck state, add priority gate to skip model-fallback
  when runtime-fallback is active
- Fix Prometheus task system: exempt from todowrite/todoread deny
- Fix background_output: default full_session to true
- Remove orphan hooks: hashline-edit-diff-enhancer (redundant with hashline_edit
  built-in diff), task-reminder (dead code)
- Remove orphan config entries: 3 stale hook names from Zod schema
- Fix disabled_hooks schema: accept arbitrary strings for forward compatibility
- Register json-error-recovery hook in tool-guard pipeline
- Add disabled_hooks gating for question-label-truncator, task-resume-info,
  claude-code-hooks
- Update test expectations to match new behavior

src/features/background-agent/manager.ts

@@ -29,6 +29,7 @@ import {
   hasMoreFallbacks,
   selectFallbackProvider,
 } from "../../shared/model-error-classifier"
+import { transformModelForProvider } from "../../shared/provider-model-id-transform"
 import {
   DEFAULT_MESSAGE_STALENESS_TIMEOUT_MS,
   DEFAULT_STALE_TIMEOUT_MS,
@@ -364,7 +365,7 @@ export class BackgroundManager {
           setSessionTools(sessionID, tools)
           return tools
         })(),
-        parts: [{ type: "text", text: input.prompt }],
+        parts: [createInternalAgentTextPart(input.prompt)],
       },
     }).catch((error) => {
       log("[background-agent] promptAsync error:", error)
@@ -637,7 +638,7 @@ export class BackgroundManager {
           setSessionTools(existingTask.sessionID!, tools)
           return tools
         })(),
-        parts: [{ type: "text", text: input.prompt }],
+        parts: [createInternalAgentTextPart(input.prompt)],
       },
     }).catch((error) => {
       log("[background-agent] resume prompt error:", error)
@@ -1006,9 +1007,10 @@ export class BackgroundManager {
     }
 
     task.attemptCount = selectedAttemptCount
+    const transformedModelId = transformModelForProvider(providerID, nextFallback.model)
     task.model = {
       providerID,
-      modelID: nextFallback.model,
+      modelID: transformedModelId,
       variant: nextFallback.variant,
     }
     task.status = "pending"

src/features/background-agent/spawner.ts

@@ -1,7 +1,7 @@
 import type { BackgroundTask, LaunchInput, ResumeInput } from "./types"
 import type { OpencodeClient, OnSubagentSessionCreated, QueueItem } from "./constants"
 import { TMUX_CALLBACK_DELAY_MS } from "./constants"
-import { log, getAgentToolRestrictions, promptWithModelSuggestionRetry } from "../../shared"
+import { log, getAgentToolRestrictions, promptWithModelSuggestionRetry, createInternalAgentTextPart } from "../../shared"
 import { subagentSessions } from "../claude-code-session-state"
 import { getTaskToastManager } from "../task-toast-manager"
 import { isInsideTmux } from "../../shared/tmux"
@@ -146,7 +146,7 @@ export async function startTask(
         question: false,
         ...getAgentToolRestrictions(input.agent),
       },
-      parts: [{ type: "text", text: input.prompt }],
+      parts: [createInternalAgentTextPart(input.prompt)],
     },
   }).catch((error) => {
     log("[background-agent] promptAsync error:", error)
@@ -230,7 +230,7 @@ export async function resumeTask(
         question: false,
         ...getAgentToolRestrictions(task.agent),
       },
-      parts: [{ type: "text", text: input.prompt }],
+      parts: [createInternalAgentTextPart(input.prompt)],
     },
   }).catch((error) => {
     log("[background-agent] resume prompt error:", error)

src/features/background-agent/task-history.ts

@@ -59,7 +59,7 @@ export class TaskHistory {
     if (list.length === 0) return null
 
     const lines = list.map((e) => {
-      const desc = e.description.replace(/[\n\r]+/g, " ").trim()
+      const desc = e.description?.replace(/[\n\r]+/g, " ").trim() ?? ""
       const parts = [
         `- **${e.agent}**`,
         e.category ? `[${e.category}]` : null,