docs: update all docs/conventions for stateful sense, remove stale refs

Phase 4 of RFC #308: Stateful Sense refactor.

- CLAUDE.md: updated diagram, tables, examples (no more Signal)
- Cleaned stale Signal Bus / DrizzleDB / _signals / retention refs
  across READMEs, .cursor rules, copilot instructions, .knowledge
- Removed drizzle-orm from core package.json (no longer used)
- Updated pnpm-lock.yaml

Refs #308

docs/coding-conventions.md

@@ -8,25 +8,29 @@
 
 ```typescript
 // ✅ Good
-type Signal = {
-  senseId: string
-  value: unknown
+type WorkflowLaunch = {
+  senseName: string
+  workflowName: string
   ts: number
 }
 
-function createSignal(senseId: string, value: unknown): Signal {
-  return { senseId, value, ts: Date.now() }
+function recordWorkflowLaunch(senseName: string, workflowName: string): WorkflowLaunch {
+  return { senseName, workflowName, ts: Date.now() }
 }
 
 // ❌ Bad
-interface ISignal {
-  senseId: string
-  value: unknown
+interface IWorkflowLaunch {
+  senseName: string
+  workflowName: string
   ts: number
 }
 
-class Signal implements ISignal {
-  constructor(public senseId: string, public value: unknown, public ts: number) {}
+class WorkflowLaunch implements IWorkflowLaunch {
+  constructor(
+    public senseName: string,
+    public workflowName: string,
+    public ts: number,
+  ) {}
 }
 ```
 
@@ -65,17 +69,16 @@ type SenseConfig = {
 当多个字段互斥时，用 discriminated union 代替一堆 optional：
 
 ```typescript
-// ✅ Good — 编译器保证 sense 和 workflow 不会同时出现
-type ReflexConfig =
-  | { kind: "sense"; sense: string; interval: string | null; on: string[] | null }
-  | { kind: "workflow"; workflow: string; on: string[] | null }
+// ✅ Good — 编译器保证两种 overflow 形态互斥且字段完整
+type WorkflowConfig =
+  | { concurrency: number; overflow: "drop" }
+  | { concurrency: number; overflow: "queue"; maxQueue: number }
 
-// ❌ Bad — sense 和 workflow 都 optional，运行时才知道到底填了哪个
-type ReflexConfig = {
-  sense?: string;
-  workflow?: string;
-  interval?: string;
-  on?: string[];
+// ❌ Bad — 字段一堆 optional，运行时才知道到底填了哪种并发策略
+type WorkflowConfig = {
+  concurrency?: number;
+  overflow?: string;
+  maxQueue?: number;
 }
 ```
 
@@ -103,9 +106,9 @@ export default function startEngine() { ... }
 
 | 类型 | 风格 | 示例 |
 |------|------|------|
-| 文件 | kebab-case | `signal-bus.ts` |
-| 类型 | PascalCase | `SignalBus` |
-| 函数/变量 | camelCase | `createSignalBus` |
+| 文件 | kebab-case | `sense-scheduler.ts` |
+| 类型 | PascalCase | `SenseScheduler` |
+| 函数/变量 | camelCase | `createSenseScheduler` |
 | 常量 | UPPER_SNAKE | `MAX_RETRY_COUNT` |
 | 泛型参数 | 单字母或描述性 | `T`, `TValue` |