chore(copy): em-dash sweep across user-facing JSX text + bump lint to error

Replaced 174 em-dashes (—) with " - " (space-hyphen-space) across 49
files in src/components + src/app. The em-dash reads as a tell-tale
"AI-generated" marker per the user's design feedback; hyphens with
spaces preserve the connector semantics without the AI tint.

Touched only lines outside pure-comment context (// /* * */). Code
comments, JSDoc, audit-log strings, structured logging strings, and
templates outside the lint scope retain their em-dashes for now —
they're not user-visible.

Also captured two remaining cases that used the `—` HTML entity
instead of the literal character (system-monitoring-dashboard,
interest-stage-picker) — replaced with a plain hyphen.

Bumped the existing `no-restricted-syntax` rule from `warn` → `error`
in eslint.config.mjs scoped to src/components/**/*.tsx +
src/app/**/*.tsx. New code reintroducing em-dashes in JSX text now
fails the lint gate.

Verified: tsc clean, vitest 1448/1448, eslint 0 em-dash warnings.

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

src/components/interests/interest-contact-log-tab.tsx

@@ -431,14 +431,14 @@ function ComposeDialogBody({
           <SheetTitle>{isEdit ? 'Edit contact log entry' : 'Log a contact'}</SheetTitle>
           <SheetDescription>
             Record the channel, the direction, and what was discussed. Optionally schedule a
-            follow-up — a reminder will be created automatically.
+            follow-up - a reminder will be created automatically.
           </SheetDescription>
         </SheetHeader>
 
         <div className="space-y-3 py-1">
           {/* Quick-template buttons. Tap one to seed the channel + direction
               + a starter summary so the rep can focus on the substance.
-              Hidden when editing — templates are a fresh-entry affordance. */}
+              Hidden when editing  -  templates are a fresh-entry affordance. */}
           {!isEdit ? (
             <div className="flex flex-wrap gap-1.5">
               {(Object.keys(TEMPLATE_SEEDS) as Template[]).map((t) => {