feat(design): foundation pass — dusty violet palette, warm parchment light, Inter + JetBrains Mono

Applies the FabledSword + Scribe iteration palette to theme.css end to
end: indigo (#7c3aed) → dusty violet (#5B4A8A) accent, cool grey →
Obsidian/Iron/Pewter dark surfaces, warm parchment (#F5F1E8) light
mode, Inter body + JetBrains Mono code loaded alongside Fraunces, and
neutral hairline scrollbars (chrome is structural, not branded).

Adds the action token set (--color-action-primary Moss,
--color-action-secondary Bronze, --color-action-destructive Oxblood,
--color-action-ghost-border Pewter) but does not yet reclassify any
buttons — surface-phase work. Buttons remain dusty-violet gradients in
the meantime, by design.

Removes deprecated --color-accent-warm; replaces concrete usages with
--color-text-secondary (dates, flavor copy) or --color-warning (paused
status). Sweeps hardcoded indigo literals in component scoped CSS so
they don't bypass the token system.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/components/NoteCard.vue

@@ -64,11 +64,11 @@ function goEdit() {
   text-decoration: none;
   color: inherit;
   background: var(--color-bg-card);
-  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06), 0 0 0 1px rgba(124, 58, 237, 0.06);
+  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06), 0 0 0 1px rgba(91, 74, 138, 0.06);
   transition: box-shadow 0.2s, transform 0.18s ease;
 }
 .note-card:hover {
-  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.10), 0 0 0 1px rgba(124, 58, 237, 0.14);
+  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.10), 0 0 0 1px rgba(91, 74, 138, 0.14);
   transform: translateY(-2px);
 }
 
@@ -89,7 +89,7 @@ function goEdit() {
 }
 .note-card.compact:hover {
   box-shadow: none;
-  background: rgba(124, 58, 237, 0.04);
+  background: rgba(91, 74, 138, 0.04);
   transform: none;
 }
 .note-title-compact {