feat: merge AI / Cloud / HomeLab into Tech pill with sub-sections

- Removed AI, Cloud, HomeLab as top-level pills
- Tech pill now matches all their slugs (ai, ml, cloud, homelab, security, dev)
- Tech view shows a sectioned front page: AI · Cloud · HomeLab · Security · Dev · Technology
- Sub-sections defined via NewsSection.techSubSections + StoryPill.subSections
- digest() extracted to makeDigest(sections:) so any pill can have sections
- Tech auto-loads 100 stories to fill its sub-sections (same as All)
- "All" Tech section in the main feed now links to Tech pill

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Jarvis/Views/Home/SignalFeedView.swift

@@ -60,15 +60,15 @@ struct SignalFeedView: View {
     private var isDigest: Bool { true }
 
     /// Front-page digest: Top Stories + up to 3 per category section, deduped.
-    private var digest: (top: [StorySummary], sections: [(NewsSection, [StorySummary])]) {
+    private func makeDigest(sections: [NewsSection]) -> (top: [StorySummary], sections: [(NewsSection, [StorySummary])]) {
         let unread = filteredStories.filter { !readStoryIds.contains($0.id) }
         let top = Array(unread.prefix(5))
         var pool = Array(unread.dropFirst(5))
         var out: [(NewsSection, [StorySummary])] = []
-        for section in NewsSection.sections {
+        for section in sections {
             var picked: [StorySummary] = [], rest: [StorySummary] = []
             for s in pool {
-                if picked.count < 3 && s.inSection(section) { picked.append(s) }
+                if picked.count < 4 && s.inSection(section) { picked.append(s) }
                 else { rest.append(s) }
             }
             pool = rest
@@ -136,8 +136,8 @@ struct SignalFeedView: View {
         .task(id: selectedPill) {
             await store.setPill(selectedPill)
             var pages = 0
-            if selectedPill == .all {
-                // Front page: pull enough stories to fill the sections.
+            // All and Tech both use multi-section layouts that need enough stories.
+            if selectedPill == .all || selectedPill == .tech {
                 while store.stories.count < 100 && store.hasMore && pages < 5 {
                     await store.loadMore(); pages += 1
                 }
@@ -262,10 +262,12 @@ struct SignalFeedView: View {
     /// Card layout for every pill. "All" gets full multi-section front page;
     /// topic pills get a hero card + flat list within that topic.
     @ViewBuilder private var digestContent: some View {
-        let d = digest
-        let headerLabel = selectedPill == .all
-            ? "TOP STORIES"
-            : selectedPill.label.uppercased()
+        let activeSections = selectedPill == .all
+            ? NewsSection.sections
+            : (selectedPill.subSections ?? [])
+        let d = makeDigest(sections: activeSections)
+        let headerLabel = selectedPill == .all ? "TOP STORIES" : selectedPill.label.uppercased()
+
         sectionHeader(headerLabel, pill: nil)
         if let lead = d.top.first {
             mainRow(lead, hero: true)
@@ -273,11 +275,10 @@ struct SignalFeedView: View {
         } else {
             emptyState.plainBlackRow()
         }
-        if selectedPill == .all {
-            ForEach(d.sections, id: \.0.id) { section, stories in
-                sectionHeader(section.label.uppercased(), pill: section.pill)
-                ForEach(stories) { mainRow($0) }
-            }
+        // "All" and pills with sub-sections (Tech) get a sectioned breakdown.
+        ForEach(d.sections, id: \.0.id) { section, stories in
+            sectionHeader(section.label.uppercased(), pill: section.pill)
+            ForEach(stories) { mainRow($0) }
         }
         readShelf
     }