fix(oauth+errors): OAuth silent refresh, quota STOP patterns, compaction loop cap

Bug fixes:
1. OAuth token refresh (#3149): buildHttpRequestInit() now attempts silent refresh
   via refresh_token before triggering full browser re-auth. Added refresh() method
   to McpOAuthProvider. Includes test isolation fix for discovery mock.

2. Quota error STOP (#3126): Added STOP_MESSAGE_PATTERNS in model-error-classifier
   that take precedence over RETRYABLE_MESSAGE_PATTERNS. Message-only quota errors
   now non-retryable. Runtime-fallback: quota_exceeded with 'retrying in' signal
   still triggers fallback (provider-managed auto-retry). Restored removed patterns.

3. Compaction loop (#3127): MAX_RECOVERY_ATTEMPTS=3 cap + additional suppression
   guard from opencode session in degradation monitor.

Also: refactored extractAutoRetrySignal to auto-retry-signal.ts, new regression
tests for quota classifier and compaction degradation monitor.

src/hooks/preemptive-compaction-degradation-monitor.regression.test.ts

@@ -0,0 +1,127 @@
+/// <reference types="bun-types" />
+
+import { afterAll, beforeEach, describe, expect, it, mock } from "bun:test"
+
+const logMock = mock(() => {})
+
+mock.module("../shared/logger", () => ({
+  log: logMock,
+}))
+
+afterAll(() => { mock.restore() })
+
+const { createPreemptiveCompactionHook } = await import("./preemptive-compaction")
+
+type AssistantHistoryMessage = {
+  info: {
+    id: string
+    role: "assistant"
+  }
+  parts: Array<{ type: string; text?: string }>
+}
+
+function createMockCtx(sessionHistory: AssistantHistoryMessage[]) {
+  return {
+    client: {
+      session: {
+        messages: mock(() => Promise.resolve({ data: sessionHistory })),
+        summarize: mock(() => Promise.resolve({})),
+      },
+      tui: {
+        showToast: mock(() => Promise.resolve({})),
+      },
+    },
+    directory: "/tmp/test",
+  }
+}
+
+function appendAssistantHistory(
+  sessionHistory: AssistantHistoryMessage[],
+  input: {
+    id: string
+    parts: AssistantHistoryMessage["parts"]
+  },
+): void {
+  sessionHistory.push({
+    info: {
+      id: input.id,
+      role: "assistant",
+    },
+    parts: input.parts,
+  })
+}
+
+function buildAssistantUpdate(input: {
+  sessionID: string
+  id: string
+  parts: unknown[]
+}) {
+  return {
+    event: {
+      type: "message.updated",
+      properties: {
+        info: {
+          id: input.id,
+          role: "assistant",
+          sessionID: input.sessionID,
+          providerID: "opencode",
+          modelID: "kimi-k2.5-free",
+          finish: true,
+          tokens: { input: 1000, output: 10, reasoning: 0, cache: { read: 0, write: 0 } },
+          parts: input.parts,
+        },
+      },
+    },
+  }
+}
+
+describe("preemptive-compaction degradation monitor regressions", () => {
+  beforeEach(() => {
+    logMock.mockClear()
+  })
+
+  it("does not re-arm monitoring after recovery-triggered compaction", async () => {
+    // given
+    const sessionHistory: AssistantHistoryMessage[] = []
+    const ctx = createMockCtx(sessionHistory)
+    const hook = createPreemptiveCompactionHook(ctx as never, {} as never)
+    const sessionID = "ses_recovery_compaction_guard"
+    const stepOnlyParts = [{ type: "step-start" }, { type: "step-finish" }]
+
+    await hook.event({
+      event: {
+        type: "session.compacted",
+        properties: { sessionID },
+      },
+    })
+
+    // when
+    appendAssistantHistory(sessionHistory, { id: "msg_1", parts: stepOnlyParts })
+    await hook.event(buildAssistantUpdate({ sessionID, id: "msg_1", parts: stepOnlyParts }))
+
+    appendAssistantHistory(sessionHistory, { id: "msg_2", parts: stepOnlyParts })
+    await hook.event(buildAssistantUpdate({ sessionID, id: "msg_2", parts: stepOnlyParts }))
+
+    appendAssistantHistory(sessionHistory, { id: "msg_3", parts: stepOnlyParts })
+    await hook.event(buildAssistantUpdate({ sessionID, id: "msg_3", parts: stepOnlyParts }))
+
+    await hook.event({
+      event: {
+        type: "session.compacted",
+        properties: { sessionID },
+      },
+    })
+
+    appendAssistantHistory(sessionHistory, { id: "msg_4", parts: stepOnlyParts })
+    await hook.event(buildAssistantUpdate({ sessionID, id: "msg_4", parts: stepOnlyParts }))
+
+    appendAssistantHistory(sessionHistory, { id: "msg_5", parts: stepOnlyParts })
+    await hook.event(buildAssistantUpdate({ sessionID, id: "msg_5", parts: stepOnlyParts }))
+
+    appendAssistantHistory(sessionHistory, { id: "msg_6", parts: stepOnlyParts })
+    await hook.event(buildAssistantUpdate({ sessionID, id: "msg_6", parts: stepOnlyParts }))
+
+    // then
+    expect(ctx.client.session.summarize).toHaveBeenCalledTimes(1)
+  })
+})