fix(workspace): move Sentry feedback to bottom-left + de-mute the assistant FAB

Two issues reported on the Sentry-enabled (prod) build:

1. The auto-injected Sentry "Report an issue" actor button and the
   workspace assistant FAB both pinned to the bottom-right corner.
   Sentry's actor carries a far higher z-index, so it overlapped and
   blocked the assistant chat. (Not reproducible on localhost — Sentry
   is a no-op without a DSN there, which is why it slipped earlier.)
   Fix: set `--actor-inset: auto auto 16px 16px` on :root. Per the
   installed @sentry-internal/feedback source the actor is positioned
   via `inset: var(--actor-inset)` (default bottom-right); this
   cascades into the widget shadow DOM exactly like the existing
   --actor-* theme props, moving the trigger to the BOTTOM-LEFT —
   opposite the assistant FAB (which keeps bottom-right). No code/JS
   change, no Sentry option needed.

2. The assistant FAB's blue looked muted vs the app's other electric-
   blue buttons. Its base gradient was already identical to
   .rd-btn-primary, but an always-on cursor-highlight radial
   (rgba(255,255,255,0.30) over ~55%) washed it out even at rest.
   Dropped the radial layer so .rd-fab renders the exact same crisp
   linear-gradient(180deg, var(--accent-strong) 0%, #114be9 100%) as
   the primary buttons. Verified on localhost: computed background now
   matches; radial gone. (The now-unused --rd-fab-x/y mousemove vars
   are harmless, left in place.)

CSS-only. FAB color verified locally; the Sentry reposition manifests
only on the DSN-configured build (verify on prod after deploy).

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

Author: LEANDERANTONY

frontend/src/app/globals.css

@@ -21,6 +21,16 @@
   --actor-color: #ffffff;
   --actor-hover-background: #4171ff;
   --actor-border: 1px solid rgba(170, 195, 255, 0.30);
+  /* Pin the trigger to the BOTTOM-LEFT (Sentry's default is
+     bottom-right, `inset: var(--actor-inset)` in @sentry-internal/
+     feedback). The workspace assistant FAB owns bottom-right; without
+     this the auto-injected widget overlapped/blocked it (Sentry's
+     actor carries a far higher z-index). `inset` is top/right/bottom/
+     left → bottom-left with a 16px gutter mirroring Sentry's ~1rem
+     default spacing. Cascades into the shadow DOM exactly like the
+     --actor-* theme props above. (No effect locally — Sentry is a
+     no-op without a DSN — manifests on the Sentry-enabled build.) */
+  --actor-inset: auto auto 16px 16px;
 }
 
 * {
@@ -7055,12 +7065,13 @@ code {
   height: 54px;
   border-radius: 999px;
   border: 1px solid rgba(140, 175, 255, 0.45);
-  /* Layered gradient with a CURSOR-FOLLOWING highlight (--rd-fab-x/y
-     CSS vars updated on mousemove). Defaults to a fixed upper-left
-     position when the cursor isn't over the button. */
-  background:
-    radial-gradient(circle at var(--rd-fab-x, 30%) var(--rd-fab-y, 25%), rgba(255, 255, 255, 0.30), transparent 55%),
-    linear-gradient(180deg, var(--accent-strong) 0%, #114be9 100%);
+  /* Same crisp electric-blue gradient as .rd-btn-primary so the FAB
+     reads as a peer of the app's other primary buttons. (Previously a
+     white radial-highlight layer sat on top — even at rest it washed
+     ~55% of the button to rgba(255,255,255,0.30), muting the blue;
+     dropped for color parity. The --rd-fab-x/y mousemove vars are now
+     unused — harmless, left in place.) */
+  background: linear-gradient(180deg, var(--accent-strong) 0%, #114be9 100%);
   color: white;
   display: grid;
   place-items: center;