feat(packages): add dsh-plugin-browserskill — DeepSeek Harness tools for bsk

Add a new monorepo package that registers BrowserSkill (bsk) browser
automation as model-visible tools in DeepSeek Harness (dsh):

- 11 tools mapping to bsk CLI --json commands: session start/stop/list,
  navigate, snapshot, observe, click, fill, press, screenshot, emulate
- multi-session support: optional session arg with a current-session
  pointer, session id echoed in every result, configurable concurrency
  cap (default 5), and dispose-time cleanup of plugin-started sessions
- cancellation: exec.signal aborts kill the underlying bsk child process
- terminal-style UI cards (command line as the call card, output as the
  result card); screenshots inline the PNG through the host attachment
  store when the model route accepts image input, else return the path
- config: bskPath / defaultTimeoutMs / maxSessions via Schemastery schema
- install guidance when the bsk binary is missing; bsk JSON error
  envelopes (code/message/hint) surfaced to the model
- unit tests mock the bsk runner (no real browser required); the root
  lint script now also runs the package's typecheck + tests so the
  existing CI frontend job covers the new package (a dedicated CI job
  diff is provided in the PR; the pushing token lacks workflow scope)

packages/dsh-plugin-browserskill/package.json

@@ -0,0 +1,54 @@
+{
+  "name": "dsh-plugin-browserskill",
+  "description": "DeepSeek Harness tool plugin that exposes BrowserSkill (bsk) browser automation to the model",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.mjs",
+  "types": "lib/index.d.mts",
+  "exports": {
+    ".": {
+      "types": "./lib/index.d.mts",
+      "default": "./lib/index.mjs"
+    },
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "lib",
+    "cordis.patch.yml"
+  ],
+  "dsh": {
+    "bundle": {
+      "patch": "./cordis.patch.yml"
+    }
+  },
+  "scripts": {
+    "build": "tsdown",
+    "typecheck": "tsc --noEmit",
+    "test": "vitest run"
+  },
+  "peerDependencies": {
+    "@deepseek-ai/cordis": "^4.0.1",
+    "@deepseek-ai/dsh-tools": "^0.1.0-rc.6"
+  },
+  "peerDependenciesMeta": {
+    "@deepseek-ai/dsh-attachment": {
+      "optional": true
+    },
+    "@deepseek-ai/dsh-llm": {
+      "optional": true
+    }
+  },
+  "devDependencies": {
+    "@deepseek-ai/cordis": "^4.0.1",
+    "@deepseek-ai/dsh-agent": "^0.1.0-rc.6",
+    "@deepseek-ai/dsh-attachment": "^0.1.0-rc.6",
+    "@deepseek-ai/dsh-llm": "^0.1.0-rc.6",
+    "@deepseek-ai/dsh-tools": "^0.1.0-rc.6",
+    "@deepseek-ai/schemastery": "^3.18.1",
+    "@types/node": "^22.10.0",
+    "tsdown": "^0.22.14",
+    "typescript": "^5.8.0",
+    "vitest": "^4.1.6"
+  }
+}