Implement hrpc with streaming and wire into setup

- Add spec/hyperschema and spec/hrpc codegen (scripts/build-hrpc.js)
  with unary, request/response-stream, duplex, and send-only commands
- Run build:hrpc and build:protomux from install.sh so setup is one-step
- Native host: add attachHrpc (Protomux channel + generated HRPC),
  handlers for ping, streamSum, fetchStream, duplex, notify
- Load HRPC lazily so missing spec does not crash host; use bare-stream
  for Duplex under Bare; add bare-stream, compact-encoding deps

native-host/package-lock.json

@@ -11,11 +11,15 @@
         "autobase": "^7.25.0",
         "b4a": "^1.6.7",
         "bare-process": "^4.1.2",
+        "bare-stream": "^2.6.5",
+        "compact-encoding": "^2.18.0",
         "corestore": "^7.0.0",
+        "hrpc": "^4.3.0",
         "hyperbee": "^2.27.0",
         "hypercore": "^11.0.0",
         "hyperdb": "^5.0.0",
         "hyperdrive": "^13.0.0",
+        "hyperschema": "^1.19.0",
         "hyperswarm": "^4.10.1",
         "protomux": "^3.10.0"
       },
@@ -213,6 +217,25 @@
         "bare-tty": "^5.0.0"
       }
     },
+    "node_modules/bare-rpc": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/bare-rpc/-/bare-rpc-1.1.0.tgz",
+      "integrity": "sha512-8cDLnat9IROS5cdVmsaTTvtws4drayZksTYYMd6VXqBWOEowOeztZlekO9DepxMf+q4+FBQStqTyso2BXqvYMg==",
+      "dependencies": {
+        "b4a": "^1.6.6",
+        "bare-stream": "^2.1.3",
+        "compact-encoding": "^2.15.0",
+        "safety-catch": "^1.0.2"
+      },
+      "peerDependencies": {
+        "bare-buffer": "*"
+      },
+      "peerDependenciesMeta": {
+        "bare-buffer": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/bare-semver": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/bare-semver/-/bare-semver-1.0.2.tgz",
@@ -467,6 +490,17 @@
       "resolved": "https://registry.npmjs.org/generate-string/-/generate-string-1.0.1.tgz",
       "integrity": "sha512-IfTY0dKZM43ACyGvXkbG7De7WY7MxTS5VO6Juhe8oJKpCmrYYXoqp/cJMskkpi0k9H8wuXq0H+eI898/BCqvXg=="
     },
+    "node_modules/hrpc": {
+      "version": "4.3.0",
+      "resolved": "https://registry.npmjs.org/hrpc/-/hrpc-4.3.0.tgz",
+      "integrity": "sha512-CdZSI8jx7x7Kzrb46Vx/IixFT/dZ4rYPRuT1Z7W6ZuJUSJxlcRFTirjUPmTt9HaFhUM3dxDzvTkqp6LY01jViA==",
+      "dependencies": {
+        "b4a": "^1.6.7",
+        "bare-rpc": "^1.1.0",
+        "hyperschema": "^1.10.4",
+        "streamx": "^2.22.0"
+      }
+    },
     "node_modules/hyperbee": {
       "version": "2.27.3",
       "resolved": "https://registry.npmjs.org/hyperbee/-/hyperbee-2.27.3.tgz",