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-protocol/src/index.ts

@@ -1,56 +0,0 @@
-// ── Types ──────────────────────────────────────────────────────────
-
-export type {
-  ContentMerkleNode,
-  StartNode,
-  StartNodePayload,
-  StateNode,
-  StateNodePayload,
-} from "./cas-types.js";
-
-export type {
-  AdapterBinding,
-  AdapterFn,
-  AdvanceOutcome,
-  AgentContext,
-  AgentFn,
-  CasStore,
-  ExtractFn,
-  ExtractResult,
-  FALLBACK,
-  LlmProvider,
-  ModeratorCondition,
-  ModeratorContext,
-  ModeratorTable,
-  ModeratorTransition,
-  ProviderConfig,
-  ResolvedModel,
-  Result,
-  RoleDefinition,
-  RoleFn,
-  RoleMeta,
-  RoleOutput,
-  RoleResult,
-  RoleStep,
-  StartStep,
-  ThreadContext,
-  WorkflowCompletion,
-  WorkflowConfig,
-  WorkflowDefinition,
-  WorkflowDescriptor,
-  WorkflowFn,
-  WorkflowGraph,
-  WorkflowGraphEdge,
-  WorkflowResult,
-  WorkflowRoleDescriptor,
-  WorkflowRoleSchema,
-  WorkflowRuntime,
-} from "./types.js";
-
-// ── Constants ──────────────────────────────────────────────────────
-
-export { END, START } from "./types.js";
-
-// ── Constructor functions ──────────────────────────────────────────
-
-export { err, ok } from "./result.js";