agent: lumotia-rebrand — data dir migration shim + paths.rs rename

Phase 5 of the rebrand cascade per locked decision D1 (migrate in place).

crates/core/src/paths.rs:
- Hardcoded subdir strings renamed: magnotia/Magnotia -> lumotia/Lumotia
  across all four OS branches (Linux XDG + dot-legacy, macOS Application
  Support, Windows LOCALAPPDATA, fallback dot-dir).
- Database filename: magnotia.db -> lumotia.db.
- Test path fixtures renamed: /tmp/magnotia-test -> /tmp/lumotia-test.
- New MigrationStatus enum (Migrated / TargetAlreadyExists / NoLegacyFound).
- New migrate_legacy_data_dir() that probes the platform-correct legacy
  magnotia path, renames it to the lumotia equivalent via fs::rename, and
  also renames magnotia.db -> lumotia.db inside if found. Idempotent: safe
  to call on every boot. Refuses to overwrite an existing lumotia dir to
  protect user data.
- Four new unit tests covering all branches via the test-friendly
  migrate_legacy_data_dir_inner that takes an explicit legacy path.

crates/storage/src/database.rs:
- New migrate_legacy_setting_keys(pool) that renames any settings rows
  with key matching magnotia_* to lumotia_*. Single SQL UPDATE with
  NOT EXISTS guard so it leaves rows alone if a lumotia_ row already
  exists. Re-exported from lib.rs.

src-tauri/src/lib.rs:
- Calls migrate_legacy_data_dir(&app_data_dir()) at the start of setup()
  BEFORE database_path() resolves the now-renamed dir. Logs migration
  outcome to lumotia_startup tracing target.
- Calls migrate_legacy_setting_keys(&db) immediately after init_db
  returns. Logs only when rows are actually renamed.

src-tauri/src/{lib,commands/{diagnostics,rituals,transcripts}}.rs +
crates/storage/src/database.rs:
- All in-code references to magnotia_preferences, magnotia_history (in
  comments), and magnotia_morning_triage_last_shown renamed to lumotia_*.

cargo build --workspace passes. cargo test --workspace: 334 pass, 0 fail
(up from 330; +4 paths::tests).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src-tauri/src/commands/diagnostics.rs

@@ -335,7 +335,7 @@ async fn generate_diagnostic_report_inner(
 
     if opts.include_settings {
         out.push_str("## Settings (sanitised)\n\n");
-        match lumotia_storage::get_setting(&state.db, "magnotia_preferences").await {
+        match lumotia_storage::get_setting(&state.db, "lumotia_preferences").await {
             Ok(Some(json)) => {
                 out.push_str("```json\n");
                 out.push_str(&sanitise_preferences_json(&json));

src-tauri/src/commands/rituals.rs

@@ -8,13 +8,13 @@
 //!
 //! Stored under the existing SQLite settings table via
 //! `lumotia_storage::{get_setting, set_setting}` — same bag as
-//! `magnotia_preferences`.
+//! `lumotia_preferences`.
 
 use lumotia_storage::{get_setting, set_setting};
 
 use crate::AppState;
 
-const LAST_TRIAGE_KEY: &str = "magnotia_morning_triage_last_shown";
+const LAST_TRIAGE_KEY: &str = "lumotia_morning_triage_last_shown";
 
 /// Returns the YYYY-MM-DD date string stored on the last successful
 /// morning triage dismissal, or `None` if the user has never been

src-tauri/src/commands/transcripts.rs

@@ -28,7 +28,7 @@ use crate::AppState;
 ///
 /// Task 2.5 — `starred`, `manualTags`, `template`, `language`, `segmentsJson`
 /// were added to back the viewer metadata that previously lived only in the
-/// removed `magnotia_history` localStorage cache.
+/// removed `lumotia_history` localStorage cache.
 #[derive(Debug, Clone, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct TranscriptDto {

src-tauri/src/lib.rs

@@ -12,9 +12,13 @@ use sqlx::SqlitePool;
 use tauri::Manager;
 use tracing_subscriber::EnvFilter;
 
+use lumotia_core::paths::{migrate_legacy_data_dir, MigrationStatus};
 use lumotia_core::types::EngineName;
 use lumotia_llm::LlmEngine;
-use lumotia_storage::{database_path, get_setting, init as init_db, prune_error_log, set_setting};
+use lumotia_storage::{
+    app_data_dir, database_path, get_setting, init as init_db, migrate_legacy_setting_keys,
+    prune_error_log, set_setting,
+};
 
 /// How long to retain `error_log` rows. Pruned once on startup.
 /// 90 days is long enough to triage "this happened a few weeks ago"
@@ -97,7 +101,7 @@ async fn save_preferences(
     state: tauri::State<'_, AppState>,
     preferences: String,
 ) -> Result<(), String> {
-    set_setting(&state.db, "magnotia_preferences", &preferences)
+    set_setting(&state.db, "lumotia_preferences", &preferences)
         .await
         .map_err(|e| e.to_string())
 }
@@ -220,6 +224,29 @@ pub fn run() {
 
     builder
         .setup(|app| {
+            // One-shot legacy data-dir migration: rename ~/.local/share/magnotia
+            // (and macOS/Windows equivalents) to the lumotia path on first
+            // launch after the rebrand. Safe to call every boot — idempotent.
+            let t_migrate = Instant::now();
+            let new_data_dir = app_data_dir();
+            match migrate_legacy_data_dir(&new_data_dir) {
+                Ok(MigrationStatus::Migrated { from, to, renamed_db }) => tracing::info!(
+                    target: "lumotia_startup",
+                    elapsed_ms = t_migrate.elapsed().as_millis(),
+                    from = %from.display(),
+                    to = %to.display(),
+                    renamed_db,
+                    "migrated legacy magnotia data dir to lumotia"
+                ),
+                Ok(MigrationStatus::TargetAlreadyExists { .. }) => {}
+                Ok(MigrationStatus::NoLegacyFound) => {}
+                Err(e) => tracing::warn!(
+                    target: "lumotia_startup",
+                    error = %e,
+                    "legacy data dir migration failed — continuing with new path"
+                ),
+            }
+
             // Initialise database and startup settings in one runtime entry.
             let db_path = database_path();
             let (db, init_script) = tauri::async_runtime::block_on(async {
@@ -229,6 +256,25 @@ pub fn run() {
                     .map_err(|e| Box::new(e) as Box<dyn std::error::Error>)?;
                 tracing::info!(target: "lumotia_startup", elapsed_ms = t0.elapsed().as_millis(), "DB init complete");
 
+                // One-shot settings-key migration: rename any leftover
+                // `magnotia_*` rows from the magnotia era to `lumotia_*`.
+                // Idempotent; logs only when rows are actually renamed.
+                let t_keys = Instant::now();
+                match migrate_legacy_setting_keys(&db).await {
+                    Ok(0) => {}
+                    Ok(n) => tracing::info!(
+                        target: "lumotia_startup",
+                        rows_renamed = n,
+                        elapsed_ms = t_keys.elapsed().as_millis(),
+                        "renamed legacy magnotia_* settings keys to lumotia_*"
+                    ),
+                    Err(e) => tracing::warn!(
+                        target: "lumotia_startup",
+                        error = %e,
+                        "settings-key migration failed — continuing"
+                    ),
+                }
+
                 // Prune old `error_log` rows so the table doesn't grow unbounded
                 // across months of dogfooding. Best-effort — a prune failure is
                 // not worth blocking startup over.
@@ -247,7 +293,7 @@ pub fn run() {
 
                 // Load saved preferences for webview injection.
                 let t1 = Instant::now();
-                let prefs_json = get_setting(&db, "magnotia_preferences").await.unwrap_or(None);
+                let prefs_json = get_setting(&db, "lumotia_preferences").await.unwrap_or(None);
                 tracing::info!(target: "lumotia_startup", elapsed_ms = t1.elapsed().as_millis(), "preferences load complete");
                 let init_script = build_preferences_script(prefs_json);