agent: lumotia-rebrand — rust workspace crates magnotia-* -> lumotia-*

Phase 2 of the rebrand cascade. Renames all 9 workspace crates from
magnotia-* to lumotia-* plus the src-tauri binary crate name:

- magnotia-ai-formatting   -> lumotia-ai-formatting
- magnotia-audio           -> lumotia-audio
- magnotia-cloud-providers -> lumotia-cloud-providers
- magnotia-core            -> lumotia-core
- magnotia-hotkey          -> lumotia-hotkey
- magnotia-llm             -> lumotia-llm
- magnotia-mcp             -> lumotia-mcp
- magnotia-storage         -> lumotia-storage
- magnotia-transcription   -> lumotia-transcription
- magnotia                 -> lumotia (src-tauri binary)
- magnotia_lib             -> lumotia_lib (src-tauri lib target)

Crate directories (crates/audio/ etc.) stay as-is; only the Cargo.toml
[package] name field changes plus all consumer module imports
(magnotia_core -> lumotia_core, etc.).

Remaining magnotia_* references at this point are intentional and
scoped to later phases: tracing targets (Phase 4), DB setting keys
magnotia_preferences/magnotia_history (Phase 5).

cargo build --workspace passes. cargo test --workspace: 330 pass, 0 fail.

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

crates/storage/src/error.rs

@@ -1,7 +1,7 @@
 //! Storage-local typed error.
 //!
 //! Backend code that wants to branch on storage failure modes pattern-matches
-//! on [`Error`] directly. The crate boundary into [`magnotia_core::error::MagnotiaError`]
+//! on [`Error`] directly. The crate boundary into [`lumotia_core::error::MagnotiaError`]
 //! flattens this into a [`MagnotiaError::Storage`] variant carrying a serde-friendly
 //! `kind`, an `operation` label, and the Display output as `detail` — so the
 //! frontend (which still receives stringified errors from Tauri commands today)
@@ -14,7 +14,7 @@
 use std::borrow::Cow;
 use std::path::PathBuf;
 
-use magnotia_core::error::{MagnotiaError, StorageKind};
+use lumotia_core::error::{MagnotiaError, StorageKind};
 
 /// Kinds of database-open operation that can fail before the pool is ready.
 #[derive(Debug, Clone, Copy)]