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/app/(dashboard)/[portSlug]/expenses/scan/page.tsx

@@ -206,14 +206,14 @@ export default function ScanReceiptPage() {
                 )}
                 {uploadMutation.isError && (
                   <span className="text-destructive">
-                    Receipt upload failed — save will still create the expense without an image.
+                    Receipt upload failed - save will still create the expense without an image.
                   </span>
                 )}
               </div>
             </div>
           ) : (
             <div className="grid gap-2 sm:grid-cols-2">
-              {/* Camera button — available on mobile devices that surface the
+              {/* Camera button  -  available on mobile devices that surface the
                   built-in capture flow when an `image/*` input has the
                   `capture` attribute. Hidden on desktop where it's a no-op. */}
               <Button
@@ -225,7 +225,7 @@ export default function ScanReceiptPage() {
                 <Camera className="mr-2 h-5 w-5" />
                 Take photo
               </Button>
-              {/* File picker — works on every platform. Phrased so the copy
+              {/* File picker  -  works on every platform. Phrased so the copy
                   fits both mobile (library/files) and desktop (drag and drop). */}
               <Button
                 type="button"
@@ -243,7 +243,7 @@ export default function ScanReceiptPage() {
               </p>
             </div>
           )}
-          {/* `image/*` is the broadest accept — includes HEIC on iOS,
+          {/* `image/*` is the broadest accept  -  includes HEIC on iOS,
               JPEG/PNG/WebP everywhere. The capture attribute on the second
               input invokes the native camera flow on mobile. */}
           <input
@@ -272,7 +272,7 @@ export default function ScanReceiptPage() {
           {scanMutation.isError && (
             <div className="mt-4 rounded-md border border-amber-300 bg-amber-50 p-3 text-xs text-amber-900 dark:border-amber-900 dark:bg-amber-950/40 dark:text-amber-200">
               <span className="font-medium">Couldn&apos;t read this receipt automatically.</span>{' '}
-              You can still fill in the details manually below — the receipt image will save with
+              You can still fill in the details manually below - the receipt image will save with
               the expense.
             </div>
           )}