feat(jobs): surface background jobs with progress, logs and controls

Add a central job registry that library scans and search index builds
report into, so background work is visible instead of buried in the
settings page.

- backend/jobs: registry with per-job ring-buffer logs, capability-driven
  controls, and one coalesced JobsChanged snapshot at 4Hz
- pause survives restart via a job_state table; a paused scan is adopted
  back on launch and skipped by the soft scan
- top-bar indicator, popover, details drawer and a Jobs page replacing
  the config page's scan UI; per-library start/stop retained
- scan timing breakdown moves into the job log, Full rescan to the Jobs
  page; delete the orphaned library-manager component

Also add cmd/indexbuild and cmd/indexexport so the explore index can be
built once centrally rather than by every install, which today streams
~205GB from the ListenBrainz spark dump on first run. indexbuild picks
build/refresh/rebuild from index state; the Gitea workflow runs it on
push, weekly, or manually and publishes only when content changed.

fresh-install no longer defaults YJ_HOME under /tmp: it is tmpfs on most
distros, and the import needs ~6GB of real disk.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

frontend/wailsjs/go/explore/Service.d.ts

@@ -2,6 +2,11 @@
 // This file is automatically generated. DO NOT EDIT
 import {explore} from '../models';
 import {context} from '../models';
+import {jobs} from '../models';
+
+export function AdoptPausedIndexBuild():Promise<void>;
+
+export function BackfillLibraryDiscographies():Promise<void>;
 
 export function BackfillLibraryLyrics():Promise<void>;
 
@@ -81,6 +86,8 @@ export function SearchLyrics(arg1:string):Promise<Array<explore.LyricsResult>>;
 
 export function SetContext(arg1:context.Context):Promise<void>;
 
+export function SetJobRegistry(arg1:jobs.Registry):Promise<void>;
+
 export function SimilarArtists(arg1:string):Promise<Array<explore.LBSimilarArtist>>;
 
 export function StartIndexBuild():Promise<void>;

frontend/wailsjs/go/explore/Service.js

@@ -2,6 +2,14 @@
 // Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
 // This file is automatically generated. DO NOT EDIT
 
+export function AdoptPausedIndexBuild() {
+  return window['go']['explore']['Service']['AdoptPausedIndexBuild']();
+}
+
+export function BackfillLibraryDiscographies() {
+  return window['go']['explore']['Service']['BackfillLibraryDiscographies']();
+}
+
 export function BackfillLibraryLyrics() {
   return window['go']['explore']['Service']['BackfillLibraryLyrics']();
 }
@@ -158,6 +166,10 @@ export function SetContext(arg1) {
   return window['go']['explore']['Service']['SetContext'](arg1);
 }
 
+export function SetJobRegistry(arg1) {
+  return window['go']['explore']['Service']['SetJobRegistry'](arg1);
+}
+
 export function SimilarArtists(arg1) {
   return window['go']['explore']['Service']['SimilarArtists'](arg1);
 }

frontend/wailsjs/go/jobs/Service.d.ts

@@ -0,0 +1,17 @@
+// Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
+// This file is automatically generated. DO NOT EDIT
+import {jobs} from '../models';
+
+export function CancelJob(arg1:string):Promise<void>;
+
+export function ClearFinishedJobs():Promise<void>;
+
+export function DismissJob(arg1:string):Promise<void>;
+
+export function GetJobLog(arg1:string):Promise<Array<jobs.LogEntry>>;
+
+export function GetJobs():Promise<Array<jobs.Job>>;
+
+export function PauseJob(arg1:string):Promise<void>;
+
+export function ResumeJob(arg1:string):Promise<void>;

frontend/wailsjs/go/jobs/Service.js

@@ -0,0 +1,31 @@
+// @ts-check
+// Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
+// This file is automatically generated. DO NOT EDIT
+
+export function CancelJob(arg1) {
+  return window['go']['jobs']['Service']['CancelJob'](arg1);
+}
+
+export function ClearFinishedJobs() {
+  return window['go']['jobs']['Service']['ClearFinishedJobs']();
+}
+
+export function DismissJob(arg1) {
+  return window['go']['jobs']['Service']['DismissJob'](arg1);
+}
+
+export function GetJobLog(arg1) {
+  return window['go']['jobs']['Service']['GetJobLog'](arg1);
+}
+
+export function GetJobs() {
+  return window['go']['jobs']['Service']['GetJobs']();
+}
+
+export function PauseJob(arg1) {
+  return window['go']['jobs']['Service']['PauseJob'](arg1);
+}
+
+export function ResumeJob(arg1) {
+  return window['go']['jobs']['Service']['ResumeJob'](arg1);
+}

frontend/wailsjs/go/library/Library.d.ts

@@ -3,6 +3,7 @@
 import {sqlcgen} from '../models';
 import {library} from '../models';
 import {context} from '../models';
+import {jobs} from '../models';
 
 export function AcquirePipelineLock():Promise<void>;
 
@@ -66,6 +67,8 @@ export function RemoveLibrary(arg1:number):Promise<library.RemovalSummary>;
 
 export function RenameLibrary(arg1:number,arg2:string):Promise<void>;
 
+export function RestorePausedScans():Promise<void>;
+
 export function ResumeScan():Promise<void>;
 
 export function ScanAllLibraries():Promise<void>;
@@ -78,6 +81,8 @@ export function SearchTracksByLibrary(arg1:string,arg2:number):Promise<Array<lib
 
 export function SetContext(arg1:context.Context):Promise<void>;
 
+export function SetJobRegistry(arg1:jobs.Registry):Promise<void>;
+
 export function SetRemovalHooks(arg1:library.RemovalHooks):Promise<void>;
 
 export function SetRescanHooks(arg1:library.RescanHooks):Promise<void>;

frontend/wailsjs/go/library/Library.js

@@ -126,6 +126,10 @@ export function RenameLibrary(arg1, arg2) {
   return window['go']['library']['Library']['RenameLibrary'](arg1, arg2);
 }
 
+export function RestorePausedScans() {
+  return window['go']['library']['Library']['RestorePausedScans']();
+}
+
 export function ResumeScan() {
   return window['go']['library']['Library']['ResumeScan']();
 }
@@ -150,6 +154,10 @@ export function SetContext(arg1) {
   return window['go']['library']['Library']['SetContext'](arg1);
 }
 
+export function SetJobRegistry(arg1) {
+  return window['go']['library']['Library']['SetJobRegistry'](arg1);
+}
+
 export function SetRemovalHooks(arg1) {
   return window['go']['library']['Library']['SetRemovalHooks'](arg1);
 }

frontend/wailsjs/go/models.ts

@@ -777,6 +777,154 @@ export namespace explore {
 
 }
 
+export namespace jobs {
+	
+	export class Caps {
+	    pausable: boolean;
+	    cancellable: boolean;
+	
+	    static createFrom(source: any = {}) {
+	        return new Caps(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.pausable = source["pausable"];
+	        this.cancellable = source["cancellable"];
+	    }
+	}
+	export class Stat {
+	    label: string;
+	    value: string;
+	
+	    static createFrom(source: any = {}) {
+	        return new Stat(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.label = source["label"];
+	        this.value = source["value"];
+	    }
+	}
+	export class Stage {
+	    name: string;
+	    state: string;
+	    current: number;
+	    total: number;
+	    error?: string;
+	
+	    static createFrom(source: any = {}) {
+	        return new Stage(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.name = source["name"];
+	        this.state = source["state"];
+	        this.current = source["current"];
+	        this.total = source["total"];
+	        this.error = source["error"];
+	    }
+	}
+	export class Job {
+	    id: string;
+	    kind: string;
+	    title: string;
+	    subtitle?: string;
+	    state: string;
+	    phase?: string;
+	    current: number;
+	    total: number;
+	    caps: Caps;
+	    stages: Stage[];
+	    stats: Stat[];
+	    error?: string;
+	    startedAt: number;
+	    updatedAt: number;
+	    endedAt?: number;
+	    logCount: number;
+	    warnCount: number;
+	    errorCount: number;
+	
+	    static createFrom(source: any = {}) {
+	        return new Job(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.id = source["id"];
+	        this.kind = source["kind"];
+	        this.title = source["title"];
+	        this.subtitle = source["subtitle"];
+	        this.state = source["state"];
+	        this.phase = source["phase"];
+	        this.current = source["current"];
+	        this.total = source["total"];
+	        this.caps = this.convertValues(source["caps"], Caps);
+	        this.stages = this.convertValues(source["stages"], Stage);
+	        this.stats = this.convertValues(source["stats"], Stat);
+	        this.error = source["error"];
+	        this.startedAt = source["startedAt"];
+	        this.updatedAt = source["updatedAt"];
+	        this.endedAt = source["endedAt"];
+	        this.logCount = source["logCount"];
+	        this.warnCount = source["warnCount"];
+	        this.errorCount = source["errorCount"];
+	    }
+	
+		convertValues(a: any, classs: any, asMap: boolean = false): any {
+		    if (!a) {
+		        return a;
+		    }
+		    if (a.slice && a.map) {
+		        return (a as any[]).map(elem => this.convertValues(elem, classs));
+		    } else if ("object" === typeof a) {
+		        if (asMap) {
+		            for (const key of Object.keys(a)) {
+		                a[key] = new classs(a[key]);
+		            }
+		            return a;
+		        }
+		        return new classs(a);
+		    }
+		    return a;
+		}
+	}
+	export class LogEntry {
+	    time: number;
+	    level: string;
+	    message: string;
+	    detail?: string;
+	
+	    static createFrom(source: any = {}) {
+	        return new LogEntry(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.time = source["time"];
+	        this.level = source["level"];
+	        this.message = source["message"];
+	        this.detail = source["detail"];
+	    }
+	}
+	export class Registry {
+	
+	
+	    static createFrom(source: any = {}) {
+	        return new Registry(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	
+	    }
+	}
+	
+
+}
+
 export namespace library {
 	
 	export class Album {

frontend/wailsjs/go/playlist/Service.d.ts

@@ -44,6 +44,8 @@ export function ImportPlaylist(arg1:string):Promise<playlist.Summary>;
 
 export function ImportPlaylists(arg1:Array<string>):Promise<Array<playlist.Summary>>;
 
+export function MaterializeUnmaterializedSmartPlaylists():Promise<void>;
+
 export function PreviewSmartPlaylist(arg1:string):Promise<Array<library.Track>>;
 
 export function RefreshSmartPlaylist(arg1:number):Promise<void>;

frontend/wailsjs/go/playlist/Service.js

@@ -82,6 +82,10 @@ export function ImportPlaylists(arg1) {
   return window['go']['playlist']['Service']['ImportPlaylists'](arg1);
 }
 
+export function MaterializeUnmaterializedSmartPlaylists() {
+  return window['go']['playlist']['Service']['MaterializeUnmaterializedSmartPlaylists']();
+}
+
 export function PreviewSmartPlaylist(arg1) {
   return window['go']['playlist']['Service']['PreviewSmartPlaylist'](arg1);
 }