feat: Add browser picker modal for URL handling (#815)

* feat: add browser picker for opening URLs

- Introduce a QML modal allowing users to select a web browser to open a given URL.
- Add a CLI command `dms open <url>` that sends a `browser.open` request to the DMS server.
- Implement server‑side Browser manager, request handling, and subscription handling to propagate open events to clients.
- Extend router and server initialization to register the new “browser” capability and include it in advertised capabilities.
- Expose `openUrlRequested` signal in DMSService.qml and connect it to the modal for seamless UI activation.
- Add a desktop entry for the Browser Picker and update the active subscriptions list to include the browser service.

* fix(browser-picker): resolve QML errors in BrowserPickerModal and DMSShell

* fix(browser-picker): fix socket discovery in dms open command

* feat: add keyboard navigation and dynamic model to browser picker

- Replace the static browsers array with a ListModel built from AppSearchService, ensuring robust iteration and future‑proofing of the browser list.
- Introduce keyboard navigation (arrow keys and Enter) using selectedIndex and gridColumns, allowing users to select a browser without a mouse.
- Reset URL, selected index, and navigation flag when the modal closes to avoid stale state.
- Redesign the grid layout to compute cell width from columns, improve focus handling, and use AppLauncherGridDelegate for a consistent UI.
- Enhance delegate behavior to update selection on hover and reset keyboard navigation state appropriately.

* feat: add searchable list/grid view to browser picker

- Introduce view mode setting (list or grid) saved in SettingsData for persistent user preference
- Add search field with real‑time filtering to quickly locate a browser by name
- Sort browsers by usage frequency from AppUsageHistoryData, falling back to alphabetical order
- Provide UI toggle buttons to switch between list and grid layouts, updating the stored setting
- Adjust keyboard navigation logic to support both layouts and improve focus handling
- Refine modal dimensions and header layout for better visual consistency
- Record launched browser usage to keep usage rankings up‑to‑date.

* feat(browser-picker): improve UX with search, view persistence, and usage tracking

Enhance BrowserPickerModal to match AppLauncher design and functionality:

UI/UX Improvements:
- Add search bar with DankTextField for filtering browsers
- Move view mode switcher (list/grid) to header next to title
- Persist view mode preference to SettingsData.browserPickerViewMode
- Match AppLauncher dimensions (520x500)
- Add proper spacing between list items
- Improve URL display with truncation (single line, elide middle)
- Remove redundant close button

Functionality:
- Implement separate browser usage tracking in SettingsData.browserUsageHistory
- Sort browsers by most recently used (independent from app launcher stats)
- Add keyboard navigation auto-scrolling for list and grid views
- Track usage count, last used timestamp, and browser name
- Filter browsers by search query

Technical:
- Add ensureVisible() functions to DankListView and DankGridView
- Store browser usage with count, lastUsed, and name fields
- Update browser list reactively on search query changes

* feat(browser-picker): use appLauncherGridColumns setting for grid layout

Make browser picker grid view respect the same column setting as the app launcher
for consistent UI across both components.

* refactor: make browser picker extensible for any MIME type/category

Refactor browser picker into a generic, reusable application picker
system that can handle any MIME type or application category, similar
to Junction. This addresses the maintainer feedback about making the
functionality "as re-usable as possible."

Frontend (QML):
- Create generic AppPickerModal component (~450 lines)
  - Configurable filtering by application categories
  - Customizable title, view modes, and usage tracking
  - Emits applicationSelected signal for flexibility
- Refactor BrowserPickerModal as thin wrapper (473 → 46 lines)
  - Demonstrates how to create specialized pickers
  - Maintains all existing browser picker functionality

Backend (Go):
- Rename browser package to apppicker for clarity
- Enhance event model to support:
  - MIME types (for future file associations)
  - Application categories (WebBrowser, Office, Graphics, etc.)
  - Request types (url, file, custom)
- Maintain backward compatibility with browser.open method
- Add new apppicker.open method for generic usage

CLI:
- Rename commands_browser.go to commands_open.go
- Add extensibility flags:
  --mime/-m: Filter by MIME type
  --category/-c: Filter by category (repeatable)
  --type/-t: Specify request type
- Examples:
  dms open file.pdf --category Office
  dms open image.png --category Graphics

DMSService:
- Add appPickerRequested signal for generic events
- Smart routing between URL and generic app picker events
- Fully backward compatible

Benefits:
- Easy to create new pickers (~15 lines of wrapper code)
- Foundation for universal file handling system
- Consistent UX across all picker types
- Ready for MIME type associations

Future extensions:
- PDF picker, image viewer picker, text editor picker
- Default application management
- File association UI in settings
- Multi-MIME type desktop file integration

* fix(cli): remove all shorthands from open command flags for consistency

Remove shorthands from --mime, --category, and --type flags to maintain
consistency and avoid conflicts with global flags.

Flags now (all long-form only):
- --category: Application categories
- --mime: MIME type
- --type: Request type

Global flags still available:
- --config, -c: Config directory path

* style: apply gofmt formatting to apppicker files

Fix formatting issues caught by CI:
- Align struct field spacing in OpenEvent
- Align variable declaration spacing
- Fix Args field alignment in cobra.Command

* feat(apppicker): add generic file opener with auto MIME detection

Implements Junction-style generic file opening capabilities:

**Backend (Go):**
- Enhanced CLI to parse file:// URIs and extract file paths
- Auto-detect MIME types from file extensions using Go's mime package
- Auto-map MIME types to desktop categories:
  - Images → Graphics, Viewer
  - Videos → Video, AudioVideo
  - Audio → Audio, AudioVideo
  - Text → TextEditor, Office (or WebBrowser for HTML)
  - PDFs → Office, Viewer
  - Office docs → Office
  - Archives → Archiving, Utility
- Added debug logging to CLI and server handler for troubleshooting

**Frontend (QML):**
- Added generic AppPickerModal (filePickerModal) for file selection
- Connected to DMSService.appPickerRequested signal
- Implemented onApplicationSelected handler with desktop entry field code support:
  - %f/%F for file paths
  - %u/%U for file:// URIs
  - Fallback to appending path if no field codes
- Separate usage tracking: filePickerUsageHistory

**Desktop Integration:**
- Updated dms-open.desktop to handle x-scheme-handler/file
- Changed category from Network;WebBrowser to Utility (more generic)
- Added text/html to MIME types

**Usage:**
Set DMS as default for specific MIME types in ~/.config/mimeapps.list:
  text/plain=dms-open.desktop
  image/png=dms-open.desktop
  application/pdf=dms-open.desktop

Then use:
  xdg-open file.txt
  xdg-open image.png
  dms open document.pdf

The picker will show appropriate apps based on auto-detected categories.

Related to #815

* fix: resolve relative path handling by converting to absolute paths

- Convert file:// URIs to absolute filesystem paths for reliable file resolution
- Convert plain local file arguments to absolute paths to ensure consistent processing
- Update log messages to display absolute paths, improving traceability
- Retain request type detection while using absolute path extensions for MIME type inference

* feat(app-picker): add Tab key view toggle and fix targetData binding

- Add Tab key to toggle between grid and list views for better keyboard UX
- Fix bug where targetData binding broke after first modal close
  - Removed targetData reset from onDialogClosed
  - Parent components (BrowserPickerModal, filePickerModal) now manage targetData
  - Fixes issue where URL/file path disappeared on subsequent opens

* fix(app-picker): properly escape URLs and file paths for shell execution

- Add shellEscape() function to wrap arguments in single quotes
- Prevents shell interpretation of special characters (&, ?, =, spaces, etc.)
- Fixes bug where URLs with query parameters were truncated at first &
- Example: http://localhost:36275/vnc.html?autoconnect=true&reconnect=true
  now properly passes the full URL instead of cutting at first &
- Applied to both BrowserPickerModal (URLs) and filePickerModal (file paths)

* fix: check error return from InitializeAppPickerManager

core/internal/server/server.go

@@ -15,6 +15,7 @@ import (
 	"time"
 
 	"github.com/AvengeMedia/DankMaterialShell/core/internal/log"
+	"github.com/AvengeMedia/DankMaterialShell/core/internal/server/apppicker"
 	"github.com/AvengeMedia/DankMaterialShell/core/internal/server/bluez"
 	"github.com/AvengeMedia/DankMaterialShell/core/internal/server/brightness"
 	"github.com/AvengeMedia/DankMaterialShell/core/internal/server/cups"
@@ -55,6 +56,7 @@ var loginctlManager *loginctl.Manager
 var freedesktopManager *freedesktop.Manager
 var waylandManager *wayland.Manager
 var bluezManager *bluez.Manager
+var appPickerManager *apppicker.Manager
 var cupsManager *cups.Manager
 var dwlManager *dwl.Manager
 var extWorkspaceManager *extworkspace.Manager
@@ -88,6 +90,21 @@ func GetSocketPath() string {
 	return filepath.Join(getSocketDir(), fmt.Sprintf("danklinux-%d.sock", os.Getpid()))
 }
 
+func FindSocket() (string, error) {
+	dir := getSocketDir()
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return "", err
+	}
+
+	for _, entry := range entries {
+		if strings.HasPrefix(entry.Name(), "danklinux-") && strings.HasSuffix(entry.Name(), ".sock") {
+			return filepath.Join(dir, entry.Name()), nil
+		}
+	}
+	return "", fmt.Errorf("no dms socket found")
+}
+
 func cleanupStaleSockets() {
 	dir := getSocketDir()
 	entries, err := os.ReadDir(dir)
@@ -201,6 +218,13 @@ func InitializeBluezManager() error {
 	return nil
 }
 
+func InitializeAppPickerManager() error {
+	manager := apppicker.NewManager()
+	appPickerManager = manager
+	log.Info("AppPicker manager initialized")
+	return nil
+}
+
 func InitializeCupsManager() error {
 	manager, err := cups.NewManager()
 	if err != nil {
@@ -357,6 +381,10 @@ func getCapabilities() Capabilities {
 		caps = append(caps, "bluetooth")
 	}
 
+	if appPickerManager != nil {
+		caps = append(caps, "browser")
+	}
+
 	if cupsManager != nil {
 		caps = append(caps, "cups")
 	}
@@ -407,6 +435,10 @@ func getServerInfo() ServerInfo {
 		caps = append(caps, "bluetooth")
 	}
 
+	if appPickerManager != nil {
+		caps = append(caps, "browser")
+	}
+
 	if cupsManager != nil {
 		caps = append(caps, "cups")
 	}
@@ -724,6 +756,31 @@ func handleSubscribe(conn net.Conn, req models.Request) {
 		}()
 	}
 
+	if shouldSubscribe("browser") && appPickerManager != nil {
+		wg.Add(1)
+		appPickerChan := appPickerManager.Subscribe(clientID + "-browser")
+		go func() {
+			defer wg.Done()
+			defer appPickerManager.Unsubscribe(clientID + "-browser")
+
+			for {
+				select {
+				case event, ok := <-appPickerChan:
+					if !ok {
+						return
+					}
+					select {
+					case eventChan <- ServiceEvent{Service: "browser.open_requested", Data: event}:
+					case <-stopChan:
+						return
+					}
+				case <-stopChan:
+					return
+				}
+			}
+		}()
+	}
+
 	if shouldSubscribe("cups") {
 		cupsSubscribers.Store(clientID+"-cups", true)
 		count := cupsSubscriberCount.Add(1)
@@ -1018,6 +1075,9 @@ func cleanupManagers() {
 	if bluezManager != nil {
 		bluezManager.Close()
 	}
+	if appPickerManager != nil {
+		appPickerManager.Close()
+	}
 	if cupsManager != nil {
 		cupsManager.Close()
 	}
@@ -1256,6 +1316,10 @@ func Start(printDocs bool) error {
 		}
 	}()
 
+	if err := InitializeAppPickerManager(); err != nil {
+		log.Debugf("AppPicker manager unavailable: %v", err)
+	}
+
 	if err := InitializeDwlManager(); err != nil {
 		log.Debugf("DWL manager unavailable: %v", err)
 	}