chore: pi family 0.85.1 -> 0.87.1 (finishTurn, transcript contexts, typebox 1.3.27)

Mechanical fallout only; semantic deltas flagged in the wave report:
- shouldStopAfterTurn -> finishTurn ({action:'end'} wrap; loop order verified
  equivalent for Wave C stranding)
- transcript rework: seeded leading SystemMessage filtered at both
  state.messages read seams (ui-stream settleWith, pi-run slice); prompt
  and tool declarations now ride the transcript
- streamOnce sites normalizeContext() (Context -> TranscriptContext)
- AgentToolResult details / ToolCall.arguments JsonValue narrowing (casts)
- AUTH_PROVIDER_KEYS regenerated (meta added); glm-5.3-flash price pin
  follows the 0.87.1 catalog (0.15/0.5/0.05)
- vanish probe: 0/12 vs 2/6 baseline; live smoke green on PORT=3004

src/core/native-messages.ts

@@ -117,7 +117,9 @@ export function newAnswerResult(
 		toolCallId,
 		toolName,
 		content: [{ type: "text", text: JSON.stringify(answer) }],
-		details: answer,
+		// 0.87.1 narrowed ToolResultMessage.details to JsonRepresentation —
+		// our payloads are JSON-safe answer structures, so the cast is honest.
+		details: answer as ToolResultMessage["details"],
 		isError: false,
 		timestamp: Date.now(),
 	};