feat(precedents): formal citation per Israeli citation rules + copy/edit UI

Until now, "case_number" was the only stored identifier for a precedent.
But a *citation per the Israeli unified citation rules* is a different
beast — it has bold parties, an unbold prefix (court abbrev + panel/
district parenthetical + case number), and an unbold trailing reporter
(נבו / פ"ד...).  Without storing it as a first-class field we couldn't
hand the chair a one-click "copy as citation" experience for pasting
into decisions.

Changes:
- Schema V19: case_law.citation_formatted TEXT (Markdown — parties
  wrapped in **…** so the copy helper can render <strong> for Word/Docs
  paste and keep plain-text fallback meaningful).
- Metadata extractor: composes citation_formatted from the document
  text per the unified citation rules, with worked examples for ע"א /
  עת"מ / ערר / בל"מ in the prompt. Refuses to store half-formed strings.
- PATCH /api/precedent-library/{id} accepts citation_formatted so the
  chair can correct LLM mistakes.
- /precedents/[id]: dedicated "מראה מקום" block with bold rendering,
  a copy-to-clipboard button (text/html + text/plain so Word keeps
  the bolds), and an inline edit textarea.
- /precedents list rows: link displays the formatted citation when
  available, with a small inline copy button — falls back to the bare
  case_number for older rows.

Backfill of existing rows happens by re-stamping the extraction queue
once V19 has rolled out and the new field is reachable.

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

web-ui/src/lib/api/precedent-library.ts

@@ -48,6 +48,7 @@ export type Precedent = {
   source_kind: string;
   chair_name: string | null;
   district: string | null;
+  citation_formatted: string;
   extraction_status: string;
   halacha_extraction_status: string;
   metadata_extraction_requested_at: string | null;
@@ -416,6 +417,7 @@ export type PrecedentPatch = Partial<{
   is_binding: boolean;
   district: string;
   chair_name: string;
+  citation_formatted: string;
 }>;
 
 export function useUpdatePrecedent() {