style: remove em/en dashes repo-wide, add CLAUDE.md rule against them (#890)

Em dashes (—) and en dashes (–) had spread across comments, docs, tests,
and a few UI strings, reading as AI-generated boilerplate rather than
house style. Replaced each with punctuation matching its context: colon
for explanatory clauses, comma for asides, plain hyphen for numeric/legal
ranges (e.g. "21-23§"), "to"/"till" for date ranges, parentheses for
paired-dash asides. messages/en.json and messages/sv.json were fixed by
hand together to keep sv/en in sync.

Left untouched where the dash is the functional subject rather than
decorative punctuation: date-range-parser.ts's separator regex,
charset-repair.ts's CP1252 byte-mapping table (and its test), the SIE
encoding mojibake docs, generic-csv.ts's minus-sign normalizer, the
agent system-prompt files that already instruct against em dashes, and
a golden iXBRL test fixture compared byte-for-byte.

Also fixes two bugs surfaced along the way: an off-by-one in
ApiKeysPanel's scope-label split (a leftover from an earlier partial
pass), and a charset-repair test that had lost the literal en-dash it
exists to verify.

Regenerated the agent atom seed migration (skills:generate) since 27
SKILL.md files changed. Added a CLAUDE.md rule against em/en dashes,
with an explicit carve-out for the functional-dash cases above.

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

components/common/CashAccountSelector.tsx

@@ -16,7 +16,7 @@ const STORAGE_KEY_PREFIX = 'Accounted:cash-account:'
 
 interface Props {
   /**
-   * Current selection — a BAS ledger account number ('1930', '1932', …).
+   * Current selection: a BAS ledger account number ('1930', '1932', …).
    * `null` would only be meaningful if "all accounts" were an option, which
    * isn't currently supported (reconciliation is always single-account).
    */
@@ -104,7 +104,7 @@ export function CashAccountSelector({
     return () => {
       cancelled = true
     }
-  // onReady excluded — lifecycle callback, shouldn't retrigger on parent renders.
+  // onReady excluded: lifecycle callback, shouldn't retrigger on parent renders.
   // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [company?.id])
 

components/common/DataState.tsx

@@ -12,7 +12,7 @@ interface DataStateProps {
   error: string | null
   /** When true (and not loading/error), render `empty` instead of `children`. */
   isEmpty?: boolean
-  /** Retry handler — typically `useFetch().refetch`. Shows a retry button. */
+  /** Retry handler: typically `useFetch().refetch`. Shows a retry button. */
   onRetry?: () => void
   /** Loading placeholder. Defaults to three skeleton rows. */
   skeleton?: React.ReactNode

components/common/FiscalYearSelector.tsx

@@ -22,7 +22,7 @@ export const ALL_YEARS_VALUE = '__all__'
 
 interface Props {
   /**
-   * Current selection. `null` means "all years" — no filter applied.
+   * Current selection. `null` means "all years": no filter applied.
    */
   value: string | null
   /**
@@ -103,7 +103,7 @@ export function FiscalYearSelector({
         const today = new Date().toISOString().split('T')[0]
         fetched = fetched.filter((p) => p.period_start <= today)
       }
-      // Newest first — most migrations list recent years at the top
+      // Newest first: most migrations list recent years at the top
       fetched.sort((a, b) => b.period_start.localeCompare(a.period_start))
       setPeriods(fetched)
       setLoaded(true)
@@ -176,7 +176,7 @@ export function FiscalYearSelector({
             )}
             {periods.map((p) => (
               <SelectItem key={p.id} value={p.id}>
-                {p.name} ({p.period_start} — {p.period_end})
+                {p.name} ({p.period_start} till {p.period_end})
                 {p.locked_at ? t('suffix_locked') : p.is_closed ? t('suffix_closed') : ''}
               </SelectItem>
             ))}

components/common/ReportDateRange.tsx

@@ -17,7 +17,7 @@ export type DateRangeValue = {
 type Preset = 'full_year' | 'ytd' | 'this_month' | 'last_month' | 'this_quarter' | 'custom'
 
 interface Props {
-  /** Selected fiscal period — bounds the range. */
+  /** Selected fiscal period: bounds the range. */
   periodStart: string
   periodEnd: string
   value: DateRangeValue
@@ -30,7 +30,7 @@ const STORAGE_KEY_PREFIX = 'Accounted:report-range-preset:'
 const PRESETS: Preset[] = ['full_year', 'ytd', 'this_month', 'last_month', 'this_quarter', 'custom']
 
 function todayIso(): string {
-  // Local calendar date — using toISOString() returns UTC, which falls a day
+  // Local calendar date: using toISOString() returns UTC, which falls a day
   // behind for Swedish users between midnight and 01:00/02:00 local time and
   // would silently truncate "today" from YTD / this-month / this-quarter.
   const d = new Date()
@@ -49,7 +49,7 @@ function clampToPeriod(date: string, periodStart: string, periodEnd: string): st
 /**
  * Resolve a preset to a concrete range inside the fiscal period.
  *
- * Endpoints are always clamped to the period — e.g. "this month" outside the
+ * Endpoints are always clamped to the period: e.g. "this month" outside the
  * period collapses to a zero-width range at whichever boundary you're nearest.
  * `full_year` returns `{}` so the API call omits the params entirely and the
  * report falls back to its full-period default (preserves cache parity with
@@ -113,7 +113,7 @@ function resolvePreset(
  *
  * Default = "Hittills i år" (YTD) which matches Fortnox/Visma. A "Hela året"
  * preset clears the range entirely so the API falls back to full-period
- * behaviour. Custom range is clamped to the fiscal period — cross-year
+ * behaviour. Custom range is clamped to the fiscal period: cross-year
  * ranges are out of scope.
  */
 export function ReportDateRange({
@@ -128,7 +128,7 @@ export function ReportDateRange({
   const [preset, setPreset] = useState<Preset>('ytd')
 
   // Restore last-used preset per company, then resolve it against the
-  // current fiscal period. The period selector lives upstream — when it
+  // current fiscal period. The period selector lives upstream: when it
   // changes, we re-resolve so the dates always sit inside the visible year.
   useEffect(() => {
     if (!company?.id || typeof window === 'undefined') return