release: v4.3.0 - fix Windows SmartScreen blocking, add signing support

- Remove signAndEditExecutable:false so code signing works properly
- Add legalTrademarks and copyright metadata to build config
- Add publisherName via build.copyright (embedded in PE resources)
- Create scripts/create-selfsigned-cert.ps1 for local dev signing
- Update release.yml: build on windows-latest runner (not Wine),
  auto-sign when CSC_LINK_BASE64/CSC_KEY_PASSWORD secrets present,
  fall back to unsigned otherwise
- Add lint step to ci.yml (Phase 4.3 plan gap)
- Add .vscode/launch.json debug configs (Phase 4.3 plan gap)
- Fix .gitignore: exclude *.pfx/*.p12 cert files, track launch.json,
  fix concatenated agents.md/coverage/ lines

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

.vscode/launch.json

@@ -0,0 +1,48 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Debug Main Process",
+      "type": "node",
+      "request": "launch",
+      "cwd": "${workspaceFolder}",
+      "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/electron",
+      "windows": {
+        "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/electron.cmd"
+      },
+      "args": ["."],
+      "outputCapture": "std",
+      "env": {
+        "NODE_ENV": "development"
+      }
+    },
+    {
+      "name": "Debug Renderer Process",
+      "type": "chrome",
+      "request": "attach",
+      "port": 9222,
+      "webRoot": "${workspaceFolder}/src",
+      "timeout": 30000
+    },
+    {
+      "name": "Debug Main + Renderer",
+      "type": "node",
+      "request": "launch",
+      "cwd": "${workspaceFolder}",
+      "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/electron",
+      "windows": {
+        "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/electron.cmd"
+      },
+      "args": [".", "--remote-debugging-port=9222"],
+      "outputCapture": "std",
+      "env": {
+        "NODE_ENV": "development"
+      },
+      "serverReadyAction": {
+        "pattern": "listening on port ([0-9]+)",
+        "uriFormat": "http://localhost:%s",
+        "action": "debugWithChrome"
+      }
+    }
+  ]
+}