diff --git a/docs/cli.md b/docs/cli.md
index 5395127..9e4c557 100644
--- a/docs/cli.md
+++ b/docs/cli.md
@@ -437,7 +437,7 @@ JSONL (one event per line):
 {"api_version":"v1","type":"run_end","timestamp":"2026-05-01T12:01:00Z","agent_id":"agent_support","release_id":"rel_abc123",...}
 ```
 
-JSON array:
+JSON array (detected automatically when the file content starts with `[`):
 ```json
 [
   {"api_version":"v1","type":"run_end","timestamp":"2026-05-01T12:00:00Z",...},
@@ -445,6 +445,14 @@ JSON array:
 ]
 ```
 
+**Edge cases:**
+
+| Input | Outcome |
+|-------|---------|
+| Empty file (0 bytes or whitespace only) | Exits `0`, prints `Inserted 0 events`. Safe to ingest placeholder files. |
+| Malformed JSONL (invalid JSON on any non-blank line) | Exits `1` with a parse error. Already-inserted rows from earlier lines remain. |
+| JSON array file | Entire file parsed as a JSON array; blank lines inside the JSON are valid. |
+
 See [http-api.md § POST /v1/events](http-api.md) for the full `RunEvent` field reference.
 
 ---
diff --git a/docs/operations-and-policy.md b/docs/operations-and-policy.md
index ebc5fbe..2638501 100644
--- a/docs/operations-and-policy.md
+++ b/docs/operations-and-policy.md
@@ -106,6 +106,28 @@ cost = (input_tokens / 1000) * input_usd_per_1k
 
 Runs are averaged across all events in the window to produce `cost_per_run_usd`.
 
+### Multi-provider and cross-model diffs
+
+Baseline and candidate releases are costed **independently using their own
+`spec.pricing_reference`**. This means:
+
+- A baseline on `openai/2024-02` and a candidate on `anthropic/2026-04` is a valid diff.
+- A baseline using `gpt-4o` and a candidate using `gpt-4.1` on the same pricing table is
+  also valid, as long as both model names have entries in their respective pricing tables.
+
+When the provider, pricing version, or model differs between the two sides, the
+`DiffOutcome` sets `pricing_or_model_changed = True`. This surfaces as:
+
+- **CLI:** `NOTE: cost delta includes pricing/model assumption changes (pricing reference
+  and/or model differ).` printed after the diff output.
+- **HTTP API (`POST /v1/diff`):** `pricing.pricing_or_model_changed: true` in the response.
+- **Web UI:** an `fd-alert--warn` callout on the Diff page naming both sides' pricing
+  references.
+
+The warning is informational — the diff still completes and policy is still evaluated.
+Treat the cost delta with caution when this flag is set, because price changes and model
+changes are conflated in the delta value.
+
 ### `compute_diff` vs. `promote_release` / `rollback_release`: filter scope
 
 `compute_diff` supports optional `tenant_id` and `task_id` filters in addition to
diff --git a/docs/web-ui.md b/docs/web-ui.md
index 568d1e1..a446fb6 100644
--- a/docs/web-ui.md
+++ b/docs/web-ui.md
@@ -153,6 +153,11 @@ On submit, the raw diff response is parsed and rendered as:
 
 - **Summary card:** policy badge (PASS / FAIL), failure reasons list, sample counts and
   confidence label.
+- **Pricing/model-change callout:** when the diff response has
+  `pricing.pricing_or_model_changed === true`, a `fd-alert--warn` strip is shown below the
+  summary card. It displays the baseline and candidate
+  `provider/pricing_version model` pairs and notes that the cost delta includes pricing and
+  model assumption changes. This mirrors the `NOTE:` line in the CLI `release diff` output.
 - **Metric cards:** cost/run (USD), latency avg (ms), error rate — each showing baseline,
   candidate, and delta.
 - **Raw diff JSON** panel (collapsed by default via `JsonPanel`).
@@ -183,8 +188,19 @@ Both **Promote** and **Rollback** buttons are disabled while any request is in f
 any network call with an inline error.
 
 After a successful mutation:
-1. The API response JSON is shown in a `JsonPanel` (open by default).
-2. `notifyTimelineMutated()` is called, refreshing `OverviewPage` automatically.
+1. A structured **outcome card** is rendered showing:
+   - Action type (Promotion / Rollback) and a **Policy PASS/FAIL badge**.
+   - **Pointer** badge — `Updated` (green) when the promoted pointer changed, `Unchanged`
+     (neutral) when policy blocked the update.
+   - Metric tiles for **Action ID**, **Release**, **Baseline**, and **Reason**.
+   - Any policy failure reasons as a list under the metric grid.
+2. The raw API response JSON is available in a collapsed `JsonPanel` below the outcome card.
+3. `notifyTimelineMutated()` is called, refreshing `OverviewPage` automatically.
+
+The `pickOutcome` helper in `ActionsPage.tsx` coerces the `POST /v1/promote` or
+`POST /v1/rollback` 200-response into an `ActionOutcomePayload`. If the response does not
+match the documented contract (e.g. missing required fields), `pickOutcome` returns `null`
+and only the raw JSON panel is shown.
 
 **Auth:** When `VITE_FLIGHTDECK_LOCAL_API_TOKEN` is set in the build environment (or
 `.env.local` during dev), `fetchJson` adds `Authorization: Bearer <token>` to every request.
@@ -225,6 +241,28 @@ type HealthPayload = {
   /** Present on current servers; "bearer" when FLIGHTDECK_LOCAL_API_TOKEN is set. */
   mutation_auth?: "bearer" | "loopback";
 };
+
+type PolicyResultPayload = {
+  passed: boolean;
+  reasons: string[];
+  evaluated_at?: string;
+};
+
+/**
+ * Response shape for `POST /v1/promote` and `POST /v1/rollback` (HTTP 200).
+ * On HTTP 409 (policy blocked), the server wraps this in `{ detail: { message, outcome } }`.
+ * `promoted_pointer_changed` is `false` when blocked.
+ */
+type ActionOutcomePayload = {
+  action_id: string;
+  action: "promote" | "rollback";
+  release_id: string;
+  agent_id: string;
+  environment: string;
+  baseline_release_id: string | null;
+  promoted_pointer_changed: boolean;
+  policy: PolicyResultPayload;
+};
 ```
 
 ### `fetchJson<T>(path, init?): Promise<T>`