fix(core,server,web,cli): compaction tolerance, retry parity, and failure classification (#174)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

packages/core/src/interfaces.ts

@@ -148,7 +148,7 @@ export interface GenerativeModelParameters {
  *     `context_engine`;
  *   - `aborted`: user-initiated interruption — stop and hand back to the user;
  *   - `failed`: an error the retry classifier did not judge transient (params, etc.) — still
- *     retried by `context_engine` within the same run (`message` provides the display text).
+ *     retried by `context_engine` within the same run (`errorMessage` provides the display text).
  *     The classification stays honest — this is reported as `failed`, not relabelled a
  *     timeout — while the *policy* retries it, because that classifier is an allowlist and a
  *     gateway phrasing a transient fault its own way lands here;
@@ -162,12 +162,13 @@ export interface GenerativeModelParameters {
 export interface LLMOutcome {
   status: StopReason;
   /**
-   * Failure detail (`describeError` text): present on `failed` / `auth`, and on `timeout` /
+   * Error detail (`describeError` text): present on `failed` / `auth`, and on `timeout` /
    * `malformed` when a concrete transport/provider error was caught (a plain idle timeout
-   * has none). Carried onto the `request_end` event so observability (the Cost center's
-   * errors panel) can show the real reason behind a retried request.
+   * has none). Carried onto the `request_end` event as `error_message` — one name across
+   * the internal outcome and the wire — so observability (the Cost center's errors panel)
+   * can show the real reason behind a retried request.
    */
-  message?: string;
+  errorMessage?: string;
 }
 
 /**