chore: add Go version lint check, modernize issue templates (#557)

- Add go.mod version check in lint workflow (fails if go directive != 1.20)
- Add golang.org/x/sys to dependabot ignore list (newer versions require Go 1.21+)
- Fix golang.org/x/text ignore comment
- Migrate issue templates from markdown to YAML forms:
- Update PR template (dev → main, add go.mod checklist item)
- Update .gitignore for YAML issue templates

.github/ISSUE_TEMPLATE/browser_request.yml

@@ -0,0 +1,51 @@
+name: Browser Support Request
+description: Request support for a new browser
+labels: ["enhancement", "browser"]
+body:
+  - type: input
+    id: browser-name
+    attributes:
+      label: Browser Name
+      placeholder: "e.g. Waterfox, Floorp, Whale"
+    validations:
+      required: true
+
+  - type: dropdown
+    id: engine
+    attributes:
+      label: Browser Engine
+      options:
+        - Chromium-based
+        - Firefox-based
+        - Other / Unknown
+    validations:
+      required: true
+
+  - type: dropdown
+    id: platform
+    attributes:
+      label: Platform
+      multiple: true
+      options:
+        - Windows
+        - macOS
+        - Linux
+    validations:
+      required: true
+
+  - type: input
+    id: data-dir
+    attributes:
+      label: User Data Directory
+      description: The browser's profile/data directory path. You can usually find this at `chrome://version` or `about:support`.
+      placeholder: "e.g. ~/Library/Application Support/BrowserName/"
+    validations:
+      required: false
+
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional Context
+      description: Any other information about this browser (download link, encryption differences, etc.)
+    validations:
+      required: false