chore: reorganize repo — legacy packages to legacy-packages/, templates to examples/

- Move 15 old workflow-* packages to legacy-packages/ (inactive, preserved for reference)
- Rename templates/ → examples/ for clarity
- Rewrite docs/architecture.md to reflect current uwf architecture
- Active packages remain in packages/: cli-uwf, uwf-agent-hermes, uwf-agent-kit, uwf-moderator, uwf-protocol, workflow-util

小橘 🍊（NEKO Team）

packages/workflow-util-agent/README.md

@@ -1,34 +0,0 @@
-# @uncaged/workflow-util-agent
-
-Shared helpers for CLI-backed workflow agents: assemble prompts from thread context and spawn subprocesses with timeouts.
-
-Used by `@uncaged/workflow-agent-cursor` and `@uncaged/workflow-agent-hermes`. Depends on `@uncaged/workflow` for CAS reads (`getContentMerklePayload`) and `Result` typing.
-
-## Install
-
-```bash
-bun add @uncaged/workflow-util-agent @uncaged/workflow
-```
-
-In this monorepo: `workspace:*` for both packages.
-
-## Usage
-
-```typescript
-import { buildAgentPrompt, spawnCli } from "@uncaged/workflow-util-agent";
-
-const prompt = await buildAgentPrompt(agentContext);
-const result = await spawnCli("my-cli", ["--json"], { cwd: "/tmp", timeoutMs: 60_000 });
-if (!result.ok) { /* handle SpawnCliError */ }
-const stdout = result.value;
-```
-
-## API overview
-
-| Export | Description |
-|--------|-------------|
-| `buildAgentPrompt(ctx)` | System prompt + task + prior step summaries + latest body from CAS; appends `uncaged-workflow thread <id>` tool hint |
-| `spawnCli(cmd, args, { cwd, timeoutMs })` | `Promise<Result<string, SpawnCliError>>`; captures stdout, non-zero exit and spawn failures as `err` |
-| `SpawnCliConfig` | `cwd: string \| null`, `timeoutMs: number \| null` |
-| `SpawnCliError` | `non_zero_exit` \| `timeout` \| `spawn_failed` |
-| `SpawnCliResult` | Alias for `Result<string, SpawnCliError>` |