feat(registry): aliases.yaml scope synonym table + contract aliases field

- registry/aliases.yaml: scope-level synonym table for 21 built-in components
  covers api (gmail/google_sheets/telegram/line_notify/http_request),
  data (string/array/date/number/json), logic (if/foreach/switch/try_catch/wait),
  ai scopes; includes zh/en/abbrev variants
- types.ts: add optional aliases[] field to ComponentContractSchema
- CONTRIBUTING.md: explain aliases auto-merge from aliases.yaml vs manual contract aliases

Note: manual maintenance for now; aliases.yaml becomes KBDB synonym graph seed data
when KBDB is introduced.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

registry/src/types.ts

@@ -46,6 +46,10 @@ export const ComponentContractSchema = z.object({
   no_network_syscall: z.boolean().optional(),
   service_binding_key: z.string().optional(),
   description: z.string().optional(),
+  // aliases：搜尋同義詞，不作為識別符使用
+  // 從 registry/aliases.yaml 的 scope 同義詞表自動合併，也可在 contract 內手動補充
+  // 未來接入 KBDB 後，canonical_id 將獲得系統派發的唯一 hash id
+  aliases: z.array(z.string()).optional(),
   tags: z.array(z.string()).optional(),
 });