diff --git a/src/app/api/insights/chat/route.ts b/src/app/api/insights/chat/route.ts
index aedc94be7..f418a1c7e 100644
--- a/src/app/api/insights/chat/route.ts
+++ b/src/app/api/insights/chat/route.ts
@@ -567,6 +567,10 @@ Reply now as the assistant, in ${locale === "de" ? "German" : "English"}. Fetch
           user: userPrompt,
           temperature: AI_BUDGETS.coach.temperature,
           maxTokens: AI_BUDGETS.coach.maxTokens,
+          // v1.20.1 — thread the request's abort signal so a mid-generation
+          // client disconnect tears the upstream provider call down instead of
+          // paying the full token cost into a closed connection.
+          signal: request.signal,
         }),
       });
       result = fallback.result;
diff --git a/src/lib/ai/__tests__/openai-client.test.ts b/src/lib/ai/__tests__/openai-client.test.ts
index 170223801..2a94eed33 100644
--- a/src/lib/ai/__tests__/openai-client.test.ts
+++ b/src/lib/ai/__tests__/openai-client.test.ts
@@ -290,4 +290,72 @@ describe("OpenAIClient", () => {
       image_url: { url: "data:image/png;base64,AAAA" },
     });
   });
+
+  it("tags an empty-content reply with sentinel httpStatus 0 + kind for the chain classifier", async () => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn().mockResolvedValue({
+        ok: true,
+        json: () =>
+          Promise.resolve({
+            choices: [{ message: { content: "" } }],
+            usage: { total_tokens: 5 },
+          }),
+      }),
+    );
+
+    const client = new OpenAIClient({
+      apiKey: "sk-test",
+      model: "gpt-4o-mini",
+      baseUrl: "https://api.openai.com/v1",
+    });
+
+    await client
+      .generateCompletion(singleUserTurn({ system: "s", user: "u" }))
+      .then(
+        () => {
+          throw new Error("expected an empty-content throw");
+        },
+        (err: unknown) => {
+          // The throw distinguishes an empty 200-OK reply from ECONNRESET:
+          // sentinel httpStatus 0 (still classified as a hard failure, so the
+          // cascade is unchanged) + a `kind` discriminator for observability.
+          expect((err as Error).message).toContain("empty content");
+          expect((err as { httpStatus?: number }).httpStatus).toBe(0);
+          expect((err as { kind?: string }).kind).toBe("empty_response");
+        },
+      );
+  });
+
+  it("threads the caller's abort signal onto the upstream fetch", async () => {
+    const mockFetch = vi.fn().mockResolvedValue({
+      ok: true,
+      json: () =>
+        Promise.resolve({
+          choices: [{ message: { content: "ok" } }],
+          usage: { total_tokens: 1 },
+        }),
+    });
+    vi.stubGlobal("fetch", mockFetch);
+
+    const client = new OpenAIClient({
+      apiKey: "sk-test",
+      model: "gpt-4o-mini",
+      baseUrl: "https://api.openai.com/v1",
+    });
+
+    const ctrl = new AbortController();
+    await client.generateCompletion(
+      singleUserTurn({ system: "s", user: "u", signal: ctrl.signal }),
+    );
+
+    // safeFetch composes the caller signal with the timeout via AbortSignal.any,
+    // so a signal lands on the dispatched fetch init.
+    const init = mockFetch.mock.calls[0][1];
+    expect(init.signal).toBeInstanceOf(AbortSignal);
+
+    // Aborting the caller's controller propagates to the composed signal.
+    ctrl.abort();
+    expect(init.signal.aborted).toBe(true);
+  });
 });
diff --git a/src/lib/ai/anthropic-client.ts b/src/lib/ai/anthropic-client.ts
index 97162de03..349db83d2 100644
--- a/src/lib/ai/anthropic-client.ts
+++ b/src/lib/ai/anthropic-client.ts
@@ -259,7 +259,9 @@ export class AnthropicClient implements AIProvider {
       // 60 s ceiling — see openai-client.ts for the rationale.
       // v1.11.2 — base URL is user/admin-overridable; pin the connect-time DNS
       // check so a private/metadata address is rejected (SSRF/rebinding).
-      { timeoutMs: 60_000, requirePublicHost: true },
+      // v1.20.1 — compose the caller's cancel signal (Coach SSE disconnect) so
+      // a mid-generation abort tears the upstream call down early.
+      { timeoutMs: 60_000, requirePublicHost: true, signal: params.signal },
     );
 
     if (!res.ok) {
@@ -318,7 +320,16 @@ export class AnthropicClient implements AIProvider {
     // A tool_use-only reply carries no text — that is valid (F1). Only an empty
     // reply with neither text NOR a tool call is an error.
     if (!rawText && !toolCalls) {
-      throw new Error("Anthropic returned empty content");
+      // v1.20.1 — sentinel httpStatus + kind so the chain classifier can tell
+      // an empty 200-OK reply apart from a transport failure. Cascade unchanged
+      // (`status <= 0` is already a hard failure).
+      const err = new Error("Anthropic returned empty content");
+      Object.assign(err, {
+        httpStatus: 0,
+        kind: "empty_response",
+        upstream: "anthropic",
+      });
+      throw err;
     }
 
     // When we prefilled the assistant turn with `{`, the model continues
diff --git a/src/lib/ai/codex-client.ts b/src/lib/ai/codex-client.ts
index 2be9fcf8c..4bc717814 100644
--- a/src/lib/ai/codex-client.ts
+++ b/src/lib/ai/codex-client.ts
@@ -467,7 +467,9 @@ export class CodexClient implements AIProvider {
         // clients use so a long generation is not clipped by the 15 s
         // default while still bounding a tar-pit upstream.
       },
-      { timeoutMs: 60_000 },
+      // v1.20.1 — compose the caller's cancel signal (Coach SSE disconnect) so
+      // a mid-generation abort tears the upstream call down early.
+      { timeoutMs: 60_000, signal: params.signal },
     );
   }
 
@@ -492,7 +494,15 @@ export class CodexClient implements AIProvider {
     requestedSlug: string,
   ): Promise<CompletionResult> {
     if (!res.body) {
-      throw new Error("Codex returned no response body");
+      // v1.20.1 — sentinel httpStatus + kind so the chain classifier can tell
+      // a stream-level failure apart from a connect-time transport error.
+      const err = new Error("Codex returned no response body");
+      Object.assign(err, {
+        httpStatus: 0,
+        kind: "stream_failed",
+        upstream: "codex",
+      });
+      throw err;
     }
 
     const reader = res.body.getReader();
@@ -595,6 +605,10 @@ export class CodexClient implements AIProvider {
               const e = new Error(message);
               Object.assign(e, {
                 upstream: "codex",
+                // v1.20.1 — sentinel httpStatus + kind so the chain classifier
+                // distinguishes a stream-level failure from a transport error.
+                httpStatus: 0,
+                kind: "stream_failed",
                 errorCode: err?.code ?? null,
                 model: serverModel ?? requestedSlug,
               });
@@ -604,13 +618,25 @@ export class CodexClient implements AIProvider {
               const reason =
                 parsed.response?.incomplete_details?.reason ??
                 "incomplete response";
-              throw new Error(`Codex stream incomplete: ${reason}`);
+              const e = new Error(`Codex stream incomplete: ${reason}`);
+              Object.assign(e, {
+                httpStatus: 0,
+                kind: "stream_failed",
+                upstream: "codex",
+              });
+              throw e;
             }
             case "error":
             case "response.error": {
               const message =
                 parsed.error?.message ?? "Codex stream returned an error event";
-              throw new Error(message);
+              const e = new Error(message);
+              Object.assign(e, {
+                httpStatus: 0,
+                kind: "stream_failed",
+                upstream: "codex",
+              });
+              throw e;
             }
             default:
               // Unknown event types are tolerated and ignored, same
@@ -627,7 +653,16 @@ export class CodexClient implements AIProvider {
     // A function-call-only reply carries no text — valid (F1). Only an empty
     // reply with neither text NOR a tool call is an error.
     if (!content && toolCalls.length === 0) {
-      throw new Error("Codex returned empty content");
+      // v1.20.1 — sentinel httpStatus + kind so the chain classifier can tell
+      // an empty reply apart from a transport failure. Cascade unchanged
+      // (`status <= 0` is already a hard failure).
+      const err = new Error("Codex returned empty content");
+      Object.assign(err, {
+        httpStatus: 0,
+        kind: "empty_response",
+        upstream: "codex",
+      });
+      throw err;
     }
 
     return {
diff --git a/src/lib/ai/local-client.ts b/src/lib/ai/local-client.ts
index 477d9bebc..eaf30ceff 100644
--- a/src/lib/ai/local-client.ts
+++ b/src/lib/ai/local-client.ts
@@ -125,7 +125,13 @@ export class LocalOpenAICompatibleClient implements AIProvider {
           ...(params.responseFormat === "json" ? { format: "json" } : {}),
         }),
       },
-      { timeoutMs: 60_000, requirePublicHost: !allowPrivate },
+      // v1.20.1 — compose the caller's cancel signal (Coach SSE disconnect) so
+      // a mid-generation abort tears the upstream call down early.
+      {
+        timeoutMs: 60_000,
+        requirePublicHost: !allowPrivate,
+        signal: params.signal,
+      },
     );
 
     if (!res.ok) {
@@ -155,7 +161,16 @@ export class LocalOpenAICompatibleClient implements AIProvider {
 
     const content = json.choices?.[0]?.message?.content;
     if (!content) {
-      throw new Error("Local AI returned empty content");
+      // v1.20.1 — sentinel httpStatus + kind so the chain classifier can tell
+      // an empty 200-OK reply apart from a transport failure. Cascade unchanged
+      // (`status <= 0` is already a hard failure).
+      const err = new Error("Local AI returned empty content");
+      Object.assign(err, {
+        httpStatus: 0,
+        kind: "empty_response",
+        upstream: "local",
+      });
+      throw err;
     }
 
     return {
diff --git a/src/lib/ai/openai-client.ts b/src/lib/ai/openai-client.ts
index e4a8c808d..26b291296 100644
--- a/src/lib/ai/openai-client.ts
+++ b/src/lib/ai/openai-client.ts
@@ -90,7 +90,9 @@ export class OpenAIClient implements AIProvider {
       // v1.11.2 — the base URL is user/admin-overridable (BYO gateway), so pin
       // the connect-time DNS check: a base URL resolving to a private/metadata
       // address is rejected, closing the SSRF/rebinding surface.
-      { timeoutMs: 60_000, requirePublicHost: true },
+      // v1.20.1 — compose the caller's cancel signal (Coach SSE disconnect) so
+      // a mid-generation abort tears the upstream call down early.
+      { timeoutMs: 60_000, requirePublicHost: true, signal: params.signal },
     );
 
     if (!res.ok) {
@@ -124,7 +126,19 @@ export class OpenAIClient implements AIProvider {
     // A reply with tool calls and no prose is valid (F1 tool loop); only an
     // empty reply with neither content NOR tool calls is an error.
     if (!content && !toolCalls) {
-      throw new Error("OpenAI returned empty content");
+      // v1.20.1 — tag the empty-reply throw with a sentinel `httpStatus: 0` +
+      // `kind` so the provider-chain classifier can tell an empty 200-OK reply
+      // apart from a genuine transport failure (ECONNRESET, DNS, timeout) in
+      // observability. The cascade is unchanged: `isHardProviderFailure`
+      // already treats `status <= 0` as a hard failure and walks to the next
+      // provider.
+      const err = new Error("OpenAI returned empty content");
+      Object.assign(err, {
+        httpStatus: 0,
+        kind: "empty_response",
+        upstream: "openai",
+      });
+      throw err;
     }
 
     return {
diff --git a/src/lib/ai/types.ts b/src/lib/ai/types.ts
index 0e1cc8028..318becc18 100644
--- a/src/lib/ai/types.ts
+++ b/src/lib/ai/types.ts
@@ -271,6 +271,15 @@ export interface CompletionParams {
    * Mapped per provider; omitted from the wire when unset.
    */
   toolChoice?: "auto" | "none";
+  /**
+   * v1.20.1 — optional caller-owned cancellation signal. Threaded onto the
+   * client's `safeFetch` so a mid-generation client disconnect (the Coach SSE
+   * route wires `request.signal` here) tears the upstream provider request
+   * down instead of running it to completion and paying the full token cost
+   * into a closed connection. Composed with the per-client timeout inside
+   * `safeFetch`. Omitted → behaviour is unchanged (timeout-only).
+   */
+  signal?: AbortSignal;
 }
 
 export interface CompletionResult {
@@ -313,6 +322,8 @@ export function singleUserTurn(p: {
   documents?: CompletionDocument[];
   tools?: AiToolDef[];
   toolChoice?: "auto" | "none";
+  /** v1.20.1 — caller-owned cancel signal threaded to the client fetch. */
+  signal?: AbortSignal;
 }): CompletionParams {
   const images = p.images ?? [];
   const documents = p.documents ?? [];
@@ -349,6 +360,7 @@ export function singleUserTurn(p: {
     responseFormat: p.responseFormat,
     tools: p.tools,
     toolChoice: p.toolChoice,
+    signal: p.signal,
   };
 }
 
diff --git a/src/lib/notifications/__tests__/dispatcher.test.ts b/src/lib/notifications/__tests__/dispatcher.test.ts
index 1795de825..f350ec7b5 100644
--- a/src/lib/notifications/__tests__/dispatcher.test.ts
+++ b/src/lib/notifications/__tests__/dispatcher.test.ts
@@ -502,6 +502,96 @@ describe("dispatchNotification — Telegram hard reject", () => {
   });
 });
 
+describe("dispatchNotification — config parse/decrypt failure is a hard reject", () => {
+  it("malformed channel config auto-disables on first occurrence (not after 5 transient ticks)", async () => {
+    const channel = makeChannel({
+      type: "NTFY",
+      // Not valid JSON → JSON.parse throws in sendToChannel.
+      config: "{ this is not json",
+    });
+    vi.mocked(prisma.notificationChannel.findMany).mockResolvedValueOnce([
+      channel,
+    ] as never);
+
+    await dispatchNotification({
+      eventType: "SYSTEM_ALERT",
+      userId: "u-1",
+      title: "t",
+      message: "m",
+    });
+
+    // The sender is never reached on a parse failure.
+    expect(sendViaNtfyMock).not.toHaveBeenCalled();
+
+    // Channel auto-disabled immediately with the precise parse reason —
+    // NOT the misleading `give_up_after_5_failures`.
+    const updateCalls = (
+      prisma.notificationChannel.update as unknown as ReturnType<typeof vi.fn>
+    ).mock.calls;
+    const disablePayload = updateCalls.find(
+      (c) => (c[0] as { data: { enabled?: boolean } }).data?.enabled === false,
+    );
+    expect(disablePayload).toBeTruthy();
+    expect(
+      (disablePayload?.[0] as { data: { disabledReason?: string } }).data
+        .disabledReason,
+    ).toBe("ntfy_config_parse_failed");
+
+    // It is logged as a hard reject, not a transient give-up.
+    expect(auditLog).toHaveBeenCalledWith(
+      "notification.channel.auto_disabled",
+      expect.objectContaining({
+        details: expect.objectContaining({
+          reason: "ntfy_config_parse_failed",
+          kind: "hard_reject",
+        }),
+      }),
+    );
+  });
+
+  it("a genuine transient failure still takes the transient path (stays enabled, backoff set)", async () => {
+    const channel = makeChannel({
+      type: "NTFY",
+      config: JSON.stringify({ serverUrl: "https://ntfy.example", topic: "t" }),
+      consecutiveFailures: 0,
+    });
+    vi.mocked(prisma.notificationChannel.findMany).mockResolvedValueOnce([
+      channel,
+    ] as never);
+    sendViaNtfyMock.mockResolvedValueOnce({
+      ok: false,
+      hardReject: false,
+      statusCode: 503,
+      reason: "ntfy_503",
+    });
+    (prisma.notificationChannel.update as unknown as ReturnType<typeof vi.fn>)
+      .mockResolvedValueOnce({ consecutiveFailures: 1 })
+      .mockResolvedValue({});
+
+    await dispatchNotification({
+      eventType: "SYSTEM_ALERT",
+      userId: "u-1",
+      title: "t",
+      message: "m",
+    });
+
+    const updateCalls = (
+      prisma.notificationChannel.update as unknown as ReturnType<typeof vi.fn>
+    ).mock.calls;
+    // No enabled=false update → channel stays enabled, backoff scheduled.
+    const disablePayload = updateCalls.find(
+      (c) => (c[0] as { data: { enabled?: boolean } }).data?.enabled === false,
+    );
+    expect(disablePayload).toBeUndefined();
+    const cooldownPayload = updateCalls.find(
+      (c) =>
+        (c[0] as { data: { nextRetryAt?: Date } }).data?.nextRetryAt instanceof
+        Date,
+    );
+    expect(cooldownPayload).toBeTruthy();
+  });
+});
+
 describe("dispatchNotification — reminders reach Web Push without APNs", () => {
   it("a PWA-only self-hoster (WEB_PUSH channel, no APNS) still gets MEDICATION_REMINDER", async () => {
     const channel = makeChannel({ type: "WEB_PUSH" });
diff --git a/src/lib/notifications/dispatcher.ts b/src/lib/notifications/dispatcher.ts
index 9bbeadc27..cab12442e 100644
--- a/src/lib/notifications/dispatcher.ts
+++ b/src/lib/notifications/dispatcher.ts
@@ -263,9 +263,16 @@ async function sendToChannel(
     decrypted = decrypt(encryptedConfig);
   } catch {
     getEvent()?.addWarning(`Failed to decrypt ${type} channel config`);
+    // A config that can't be decrypted is a structurally-permanent failure,
+    // not a transient blip: the ciphertext / key pairing won't fix itself on
+    // a retry. Hard-reject so the channel auto-disables on first occurrence
+    // with an accurate reason, rather than burning the 5-failure transient
+    // budget and ending on the misleading `give_up_after_5_failures`. During
+    // a key-rotation gap every channel would otherwise auto-disable for the
+    // wrong reason.
     return {
       ok: false,
-      hardReject: false,
+      hardReject: true,
       reason: `${type.toLowerCase()}_config_decrypt_failed`,
     };
   }
@@ -277,9 +284,10 @@ async function sendToChannel(
         config = JSON.parse(decrypted) as TelegramChannelConfig;
       } catch {
         getEvent()?.addWarning("Failed to parse Telegram channel config");
+        // Malformed config decodes the same on every retry — permanent.
         return {
           ok: false,
-          hardReject: false,
+          hardReject: true,
           reason: "telegram_config_parse_failed",
         };
       }
@@ -291,9 +299,10 @@ async function sendToChannel(
         config = JSON.parse(decrypted) as NtfyChannelConfig;
       } catch {
         getEvent()?.addWarning("Failed to parse ntfy channel config");
+        // Malformed config decodes the same on every retry — permanent.
         return {
           ok: false,
-          hardReject: false,
+          hardReject: true,
           reason: "ntfy_config_parse_failed",
         };
       }
@@ -305,9 +314,10 @@ async function sendToChannel(
         config = JSON.parse(decrypted) as WebhookChannelConfig;
       } catch {
         getEvent()?.addWarning("Failed to parse webhook channel config");
+        // Malformed config decodes the same on every retry — permanent.
         return {
           ok: false,
-          hardReject: false,
+          hardReject: true,
           reason: "webhook_config_parse_failed",
         };
       }
@@ -319,9 +329,10 @@ async function sendToChannel(
         config = JSON.parse(decrypted) as EmailChannelConfig;
       } catch {
         getEvent()?.addWarning("Failed to parse email channel config");
+        // Malformed config decodes the same on every retry — permanent.
         return {
           ok: false,
-          hardReject: false,
+          hardReject: true,
           reason: "email_config_parse_failed",
         };
       }