agent: lumotia-rebrand — drop MagnotiaError prefix, now lumotia_core::Error

Phase 3 of the rebrand cascade per locked decision D4. MagnotiaError ->
Error in crates/core/src/error.rs (the crate name already qualifies it).
92 usages across 14 .rs files renamed via word-boundary sed.

One collision required disambiguation: lumotia_storage already had its
own local Error type (introduced by the slop-pass Area A residuals work).
crates/storage/src/error.rs aliases the imported core error as CoreError
on import; the From<Error> for CoreError boundary impl and the
CoreError::Storage construction site use the alias.

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

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

crates/audio/src/wav.rs

@@ -1,7 +1,7 @@
 use std::io::BufWriter;
 use std::path::Path;
 
-use lumotia_core::error::{MagnotiaError, Result};
+use lumotia_core::error::{Error, Result};
 use lumotia_core::types::AudioSamples;
 
 /// Append-friendly WAV writer for long-running captures.
@@ -40,10 +40,10 @@ impl WavWriter {
             bits_per_sample: 16,
             sample_format: hound::SampleFormat::Int,
         };
-        let file = std::fs::File::create(path).map_err(MagnotiaError::from)?;
+        let file = std::fs::File::create(path).map_err(Error::from)?;
         let buffered = BufWriter::new(file);
         let inner = hound::WavWriter::new(buffered, spec).map_err(|e| {
-            MagnotiaError::from(std::io::Error::other(format!("WAV create failed: {e}")))
+            Error::from(std::io::Error::other(format!("WAV create failed: {e}")))
         })?;
         Ok(Self {
             inner,
@@ -61,7 +61,7 @@ impl WavWriter {
             let clamped = sample.clamp(-1.0, 1.0);
             let int_sample = (clamped * i16::MAX as f32) as i16;
             self.inner.write_sample(int_sample).map_err(|e| {
-                MagnotiaError::from(std::io::Error::other(format!("WAV write failed: {e}")))
+                Error::from(std::io::Error::other(format!("WAV write failed: {e}")))
             })?;
         }
         self.samples_since_flush += samples.len();
@@ -78,7 +78,7 @@ impl WavWriter {
     /// boundaries (end-of-utterance, UI events) for tighter recovery.
     pub fn flush(&mut self) -> Result<()> {
         self.inner.flush().map_err(|e| {
-            MagnotiaError::from(std::io::Error::other(format!("WAV flush failed: {e}")))
+            Error::from(std::io::Error::other(format!("WAV flush failed: {e}")))
         })?;
         self.samples_since_flush = 0;
         Ok(())
@@ -90,7 +90,7 @@ impl WavWriter {
     /// that care about the unflushed tail should always finalise.
     pub fn finalize(self) -> Result<()> {
         self.inner.finalize().map_err(|e| {
-            MagnotiaError::from(std::io::Error::other(format!("WAV finalize failed: {e}")))
+            Error::from(std::io::Error::other(format!("WAV finalize failed: {e}")))
         })?;
         Ok(())
     }
@@ -106,19 +106,19 @@ pub fn write_wav(path: &Path, audio: &AudioSamples) -> Result<()> {
     };
 
     let mut writer = hound::WavWriter::create(path, spec).map_err(|e| {
-        MagnotiaError::from(std::io::Error::other(format!("WAV create failed: {e}")))
+        Error::from(std::io::Error::other(format!("WAV create failed: {e}")))
     })?;
 
     for &sample in audio.samples() {
         let clamped = sample.clamp(-1.0, 1.0);
         let int_sample = (clamped * i16::MAX as f32) as i16;
         writer.write_sample(int_sample).map_err(|e| {
-            MagnotiaError::from(std::io::Error::other(format!("WAV write failed: {e}")))
+            Error::from(std::io::Error::other(format!("WAV write failed: {e}")))
         })?;
     }
 
     writer.finalize().map_err(|e| {
-        MagnotiaError::from(std::io::Error::other(format!("WAV finalize failed: {e}")))
+        Error::from(std::io::Error::other(format!("WAV finalize failed: {e}")))
     })?;
 
     Ok(())
@@ -126,14 +126,14 @@ pub fn write_wav(path: &Path, audio: &AudioSamples) -> Result<()> {
 
 /// Read a WAV file to f32 PCM `AudioSamples`.
 ///
-/// Any per-sample decode error is surfaced as `MagnotiaError::AudioDecodeFailed`
+/// Any per-sample decode error is surfaced as `Error::AudioDecodeFailed`
 /// rather than silently dropped. A previous implementation used
 /// `filter_map(|s| s.ok())`, so a truncated or corrupt payload returned
 /// a short, silently-partial `AudioSamples` — callers got `Ok` while
 /// losing audio (flagged by the 2026-04-22 review).
 pub fn read_wav(path: &Path) -> Result<AudioSamples> {
     let reader = hound::WavReader::open(path)
-        .map_err(|e| MagnotiaError::AudioDecodeFailed(format!("WAV open failed: {e}")))?;
+        .map_err(|e| Error::AudioDecodeFailed(format!("WAV open failed: {e}")))?;
 
     let spec = reader.spec();
     let sample_rate = spec.sample_rate;
@@ -147,7 +147,7 @@ pub fn read_wav(path: &Path) -> Result<AudioSamples> {
                 sample
                     .map(|s| s as f32 / (1 << (bits_per_sample - 1)) as f32)
                     .map_err(|e| {
-                        MagnotiaError::AudioDecodeFailed(format!("WAV sample decode failed: {e}"))
+                        Error::AudioDecodeFailed(format!("WAV sample decode failed: {e}"))
                     })
             })
             .collect::<Result<Vec<f32>>>()?,
@@ -155,7 +155,7 @@ pub fn read_wav(path: &Path) -> Result<AudioSamples> {
             .into_samples::<f32>()
             .map(|sample| {
                 sample.map_err(|e| {
-                    MagnotiaError::AudioDecodeFailed(format!("WAV sample decode failed: {e}"))
+                    Error::AudioDecodeFailed(format!("WAV sample decode failed: {e}"))
                 })
             })
             .collect::<Result<Vec<f32>>>()?,