refactor(state): drop kon_history localStorage cache — SQLite canonical

src/lib/stores/page.svelte.js

@@ -75,55 +75,79 @@ export function saveProfiles() {
   } catch {}
 }
 
-// ---- History (dual-write: SQLite via Tauri = canonical, localStorage = read-cache) ----
+// ---- History (SQLite via Tauri = canonical; no localStorage cache) ----
 //
-// As of Day 4 of the upgrade plan, the canonical store is the SQLite
-// transcripts table reachable via the `add_transcript`, `list_transcripts`,
-// `update_transcript`, `delete_transcript`, `search_transcripts` Tauri
-// commands. localStorage continues to back the in-memory `history` array
-// for UI snappiness and offline browser-preview support, but the source
-// of truth is SQLite. Browser preview falls back to localStorage only.
+// The canonical store is the SQLite transcripts table reachable via the
+// `add_transcript`, `list_transcripts`, `update_transcript`,
+// `delete_transcript`, `search_transcripts` Tauri commands. The history
+// array is seeded empty on module init and hydrated from SQLite on boot
+// in the desktop runtime. Browser preview (no Tauri) shows an empty list.
+//
+// The previous `kon_history` localStorage read-cache was removed to kill
+// the cold-start flicker where the UI painted stale localStorage data and
+// then overwrote it from SQLite a tick later.
 
 import { invoke } from "@tauri-apps/api/core";
 import { hasTauriRuntime } from "$lib/utils/runtime.js";
+import { toasts } from "$lib/stores/toasts.svelte.js";
 
-const HISTORY_KEY = "kon_history";
+export const history = $state([]);
 
-function loadHistory() {
+/** Shape a TranscriptDto row from `list_transcripts` into the UI entry shape
+ *  that HistoryPage expects. UI-only fields that were never persisted to
+ *  SQLite (segments, starred, manualTags, language, template) are absent. */
+function mapTranscriptRow(row) {
+  const text = row.text ?? "";
+  return {
+    id: row.id,
+    text,
+    source: row.source ?? "",
+    title: row.title ?? "",
+    audioPath: row.audioPath ?? null,
+    duration: Number(row.duration ?? 0),
+    engine: row.engine ?? null,
+    modelId: row.modelId ?? null,
+    createdAt: row.createdAt ?? null,
+    date: row.createdAt ? new Date(row.createdAt).toLocaleString("en-GB") : "",
+    preview: text.slice(0, 120),
+  };
+}
+
+async function loadHistory() {
+  if (!hasTauriRuntime()) {
+    history.length = 0;
+    return;
+  }
   try {
-    const raw = localStorage.getItem(HISTORY_KEY);
-    if (raw) return JSON.parse(raw);
-  } catch {}
-  return [];
+    const rows = await invoke("list_transcripts", { limit: 500, offset: 0 });
+    const mapped = Array.isArray(rows) ? rows.map(mapTranscriptRow) : [];
+    history.splice(0, history.length, ...mapped);
+  } catch (err) {
+    console.error("loadHistory failed", err);
+    history.length = 0;
+    toasts.error("Failed to load history", err?.message ?? String(err));
+  }
 }
 
-export const history = $state(loadHistory());
-
-// Keep the in-memory history in sync with edits made by sibling windows
-// (e.g. the viewer saving a cleaned-up transcript). Storage events fire
-// only on *other* windows than the writer, so we won't re-enter our own
-// writes.
-if (typeof window !== "undefined") {
-  window.addEventListener("storage", (e) => {
-    if (e.key !== HISTORY_KEY || !e.newValue) return;
-    try {
-      const next = JSON.parse(e.newValue);
-      history.splice(0, history.length, ...next);
-    } catch {}
-  });
+// Hydrate history from SQLite on boot. Mirrors the tasks hydration pattern
+// further down this file.
+if (typeof window !== "undefined" && hasTauriRuntime()) {
+  loadHistory().catch(() => {});
 }
 
-export function saveHistory() {
-  try {
-    localStorage.setItem(HISTORY_KEY, JSON.stringify(history));
-  } catch {}
-}
+// `saveHistory` is retained as a no-op for callers in HistoryPage that use
+// it as a mutation hook (tag add/remove, clear-all). SQLite writes happen
+// via the specific `add_transcript` / `update_transcript` /
+// `delete_transcript` commands in the functions below; ad-hoc UI-only
+// mutations (e.g. manualTags) are session-scoped because they are not
+// backed by a SQLite column.
+export function saveHistory() {}
 
 /**
- * Add a transcript to history. Dual-writes to SQLite (canonical) and
- * localStorage (cache). The SQLite write is best-effort: if it fails,
- * we still update the in-memory + localStorage copy so the UI stays
- * responsive. The next session boot reconciles by reading SQLite first.
+ * Add a transcript to history. Writes to SQLite (canonical) and updates
+ * the in-memory `history` array. SQLite is best-effort: if it fails we
+ * keep the in-memory copy so the UI stays responsive for the session,
+ * but the entry will not survive a restart.
  *
  * `entry` shape:
  *   { id, text, source?, title?, audioPath?, duration?, engine?, modelId?,
@@ -132,10 +156,9 @@ export function saveHistory() {
  */
 export async function addToHistory(entry) {
   history.unshift(entry);
-  if (history.length > 100) history.length = 100;
-  saveHistory();
+  if (history.length > 500) history.length = 500;
 
-  if (!hasTauriRuntime()) return; // Browser preview: localStorage only.
+  if (!hasTauriRuntime()) return; // Browser preview: in-memory only.
 
   try {
     await invoke("add_transcript", {
@@ -158,22 +181,20 @@ export async function addToHistory(entry) {
       },
     });
   } catch (err) {
-    console.warn("addToHistory: SQLite dual-write failed, kept in localStorage", err);
+    console.warn("addToHistory: SQLite write failed, entry will not persist past restart", err);
   }
 }
 
 /**
  * Update text and/or title of an existing transcript. Persists to SQLite
- * via update_transcript; updates the in-memory + localStorage cache.
- * Closes the historic "rename never persists" bug from
- * architecture-review.md §13.
+ * via update_transcript; updates the in-memory entry. Closes the historic
+ * "rename never persists" bug from architecture-review.md §13.
  */
 export async function renameHistoryEntry(id, updates) {
   const idx = history.findIndex(h => String(h.id) === String(id));
   if (idx >= 0) {
     if (updates.title !== undefined) history[idx].title = updates.title;
     if (updates.text !== undefined) history[idx].text = updates.text;
-    saveHistory();
   }
 
   if (!hasTauriRuntime()) return;
@@ -193,7 +214,6 @@ export async function renameHistoryEntry(id, updates) {
 export function deleteFromHistory(index) {
   const entry = history[index];
   history.splice(index, 1);
-  saveHistory();
 
   if (!hasTauriRuntime() || !entry?.id) return;