Make Applications a real app manager, and clean up storage without the racket

Claude-Session: https://claude.ai/code/session_01Ms2FbjQy31TVf3CEvQhGM8

config/dot/quickshell/services/DefaultApps.qml

@@ -18,6 +18,16 @@ Singleton {
     property var luaAutostartEntries: []
     property string lastError: ""
 
+    // One file type at a time: the escape hatch for when a role's family is too
+    // broad, which is a real case -- SVG belongs in an editor while every other
+    // image belongs in a viewer. Kept separate from the role state because it is
+    // a search, not a setting: it is whatever was last asked for and nothing is
+    // remembered between visits.
+    property var typeMatches: []
+    property string typeQuery: ""
+    property bool typeSearchTruncated: false
+    readonly property bool searchingTypes: typeSearch.running
+
     // For the UI, which wants one answer to "is anything happening".
     //
     // Guards inside this file do NOT use it. `busy` is a binding, and a binding
@@ -56,15 +66,48 @@ Singleton {
     Process {
         id: mutationProcess
 
+        // A set-type write changes the answer the open search is showing, so
+        // the search is re-run rather than left displaying the old handler.
+        property string repeatQuery: ""
+
         onExited: (exitCode, exitStatus) => {
             if (exitCode !== 0) {
+                mutationProcess.repeatQuery = ""
                 root.lastError = "That application setting could not be changed."
                 return;
             }
+            if (mutationProcess.repeatQuery !== "") {
+                const query = mutationProcess.repeatQuery;
+                mutationProcess.repeatQuery = "";
+                root.searchTypes(query);
+            }
             root.refresh();
         }
     }
 
+    Process {
+        id: typeSearch
+
+        stdout: StdioCollector {
+            onStreamFinished: {
+                try {
+                    const payload = JSON.parse(this.text);
+                    root.typeMatches = Array.isArray(payload.types) ? payload.types : [];
+                    root.typeSearchTruncated = payload.truncated === true;
+                } catch (error) {
+                    root.typeMatches = [];
+                    root.lastError = "File types returned an unreadable response."
+                }
+            }
+        }
+        onExited: (exitCode, exitStatus) => {
+            if (exitCode !== 0) {
+                root.typeMatches = [];
+                root.lastError = "File types could not be searched."
+            }
+        }
+    }
+
     function applySnapshot(text: string): void {
         try {
             const payload = JSON.parse(text);
@@ -135,6 +178,47 @@ Singleton {
         mutationProcess.exec([root.helper, "remove-autostart", desktopId]);
     }
 
+    // Searching is over the type name and its file extensions -- "svg", "heic",
+    // ".mkv". Matching the human descriptions would mean reading the whole
+    // shared-mime-info database, some thousands of small files, per keystroke.
+    function searchTypes(query: string): void {
+        const trimmed = String(query ?? "").trim();
+        root.typeQuery = trimmed;
+        if (trimmed.length < 2) {
+            root.typeMatches = [];
+            root.typeSearchTruncated = false;
+            return;
+        }
+        if (typeSearch.running)
+            return;
+        typeSearch.exec([root.helper, "search-types", trimmed]);
+    }
+
+    function clearTypeSearch(): void {
+        root.typeQuery = "";
+        root.typeMatches = [];
+        root.typeSearchTruncated = false;
+    }
+
+    // One type, one application: the override that leaves the rest of the
+    // family where it is. The helper validates the type against what this
+    // system knows and the application against what is installed.
+    function setType(mime: string, desktopId: string): void {
+        if (mutationProcess.running)
+            return;
+        if (!/^[A-Za-z0-9][A-Za-z0-9!#$&^_.+-]*\/[A-Za-z0-9][A-Za-z0-9!#$&^_.+-]*$/.test(mime)) {
+            root.lastError = "Choose a file type from the list."
+            return;
+        }
+        if (!root.knownDesktopId(desktopId)) {
+            root.lastError = "Choose an application from the available list."
+            return;
+        }
+        root.lastError = "";
+        mutationProcess.repeatQuery = root.typeQuery;
+        mutationProcess.exec([root.helper, "set-type", mime, desktopId]);
+    }
+
     function addAutostart(desktopId: string): void {
         if (mutationProcess.running)
             return;