rename: slopsmith -> feedBack, byron -> got-feedBack

Renames across the entire codebase:
- slopsmith/Slopsmith/SLOPSMITH/SlopSmith -> feedBack/FeedBack/FEEDBACK/FeedBack
- byron/Byron/Byrongamatos -> got-feedBack/got-feedBack/got-feedBack
- /home/byron/ -> /opt/got-feedBack/
- byron@ougsoft.com -> hi@got-feedBack.org
- github.com/byrongamatos/ -> github.com/got-feedback/
- com.byron. -> com.got-feedback.
- SLOPSMITH_ env vars -> FEEDBACK_ with backward-compat fallback
- Protocol/storage strings migrated with read-old/write-new pattern
- window.slopsmith JS API -> window.feedBack (canonical) + backward-compat alias

Refs: #rename-slopsmith

plugins/tuner/visualization/analogue-gauge.js

@@ -1,5 +1,5 @@
 /**
- * Analogue gauge tuner visualization for the Slopsmith tuner plugin.
+ * Analogue gauge tuner visualization for the FeedBack tuner plugin.
  *
  * Contract: window['_tunerViz_analogue-gauge'](container) → { update(note, cents, freq), destroy() }
  *   - note: string | null  (null = no signal)

plugins/tuner/visualization/chef-mt3.js

@@ -1,5 +1,5 @@
 /**
- * CHEF MT-3 tuner visualization for the Slopsmith tuner plugin.
+ * CHEF MT-3 tuner visualization for the FeedBack tuner plugin.
  *
  * Inspired by classic chromatic pedal tuners:
  *   - Shiny black rectangular panel with chamfered edges and corner screws

plugins/tuner/visualization/default.js

@@ -1,5 +1,5 @@
 /**
- * Default (gauge) tuner visualization for the Slopsmith tuner plugin.
+ * Default (gauge) tuner visualization for the FeedBack tuner plugin.
  *
  * Contract: window._tunerViz_default(container) → { update(note, cents, freq), destroy() }
  *   - note: string | null  (null = no signal)

plugins/tuner/visualization/mace-fx-iii.js

@@ -1,5 +1,5 @@
 /**
- * Mace Fx III style tuner visualization for the Slopsmith tuner plugin.
+ * Mace Fx III style tuner visualization for the FeedBack tuner plugin.
  *
  * Inspired by hardware rack tuner displays:
  *   - Dark navy LCD background

plugins/tuner/visualization/strobe.js

@@ -1,5 +1,5 @@
 /**
- * Strobe tuner visualization for the Slopsmith tuner plugin.
+ * Strobe tuner visualization for the FeedBack tuner plugin.
  *
  * Contract: window._tunerViz_strobe(container) → { update(note, cents, freq), destroy() }
  *   - note: string | null  (null = no signal)

plugins/tuner/visualization/toilet-tuner.js

@@ -1,5 +1,5 @@
 /**
- * Toilet Tuner visualization for the Slopsmith tuner plugin.
+ * Toilet Tuner visualization for the FeedBack tuner plugin.
  *
  * Bathroom scene background; plunger slides left/right over the bowl based on
  * cents deviation; dips into bowl when in tune (±2 cents); wall calendar shows