feat(vscode-bridge): Copilot Chat bridge (OpenAI facade + JSON-RPC tools)

- Implements VS Code extension per AGENTS.md specification
- OpenAI-style HTTP facade: POST /v1/chat/completions (SSE), GET /v1/models, GET /healthz
- JSON-RPC WebSocket server with methods: mcp.fs.read/list, mcp.search.code, mcp.symbols.list, mcp.edit.applyPatch, mcp.format.apply, mcp.imports.organize
- Copilot Chat integration via vscode.chat.requestChatAccess('copilot')
- Commands: bridge.enable/disable/status with status bar indicator
- Security: localhost-only binding, optional bearer token, read-only by default
- Policy enforcement via optional .agent-policy.yaml
- Ephemeral port management with globalState persistence

Co-Authored-By: Lars Baunwall <larslb@thinkability.dk>

vscode-bridge/node_modules/yaml/dist/stringify/stringifyNumber.js

@@ -0,0 +1,26 @@
+'use strict';
+
+function stringifyNumber({ format, minFractionDigits, tag, value }) {
+    if (typeof value === 'bigint')
+        return String(value);
+    const num = typeof value === 'number' ? value : Number(value);
+    if (!isFinite(num))
+        return isNaN(num) ? '.nan' : num < 0 ? '-.inf' : '.inf';
+    let n = JSON.stringify(value);
+    if (!format &&
+        minFractionDigits &&
+        (!tag || tag === 'tag:yaml.org,2002:float') &&
+        /^\d/.test(n)) {
+        let i = n.indexOf('.');
+        if (i < 0) {
+            i = n.length;
+            n += '.';
+        }
+        let d = minFractionDigits - (n.length - i - 1);
+        while (d-- > 0)
+            n += '0';
+    }
+    return n;
+}
+
+exports.stringifyNumber = stringifyNumber;