feat(auth): auth_static_key WASM primitive + host functions

- wasi-shim gains kv_get / crypto_decrypt / crypto_sign_rs256 host
  functions with strict boundary (ENCRYPTION_KEY never exits Worker).
- registry/components/auth_static_key: TinyGo impl for API-key /
  Bearer / Basic Auth recipes (80% of supported services).
- .component-builds/auth_static_key: independent Worker at
  auth-static-key.arcrun.dev, imports wasi-shim cross-directory.
- cypher-executor/auth-dispatcher routes static_key recipes to the
  new Worker instead of credential-injector TS.

Replaces TS credential injection per
.agents/specs/arcrun/credential-primitives-wasm Phase 1.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.component-builds/auth_static_key/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "arcrun-auth-static-key",
+  "version": "1.0.0",
+  "private": true,
+  "type": "module",
+  "dependencies": {
+    "hono": "^4.7.0"
+  },
+  "devDependencies": {
+    "@cloudflare/workers-types": "^4.20250408.0",
+    "typescript": "^5.4.0",
+    "wrangler": "^4.0.0"
+  }
+}