feat: #34 citation graph + #32 wide-modal precedent edit + #13 verify

## #34 — Daphna's internal citation graph

New schema V16 (V15 was already used by proceeding_type): table
``precedent_internal_citations`` (source→cited, with cited_case_law_id
nullable for citations whose target isn't in the corpus yet) + 3
indexes (source, target, unlinked).

New service ``citation_extractor.py`` with regex patterns for ערר /
בל"מ / עע"מ / בר"מ / עמ"נ / ע"א / בג"ץ / רע"א — accepts both ``\/``
and ``-`` separators, requires actual parenthesized district label
to avoid greedy mid-paragraph captures. Resolves citations against
``case_law.case_number`` substring; default confidence 0.90 linked,
0.75 unlinked. ON CONFLICT DO NOTHING on (source, cited_case_number).

3 new MCP tools: ``extract_internal_citations``,
``list_internal_citations``, ``list_incoming_citations``. Optional
flag ``include_cited_by=True`` on ``search_internal_decisions``
appends cited-by candidates as ``match_type='cited_by'`` stubs.

Bulk-extracted from 40 internal_committee rows authored by דפנה תמיר:
**353 distinct citations, 348 stored, 96 linked / 252 unlinked**.
Top citers: 1079/24 (30), 1024/24 (19), 1009/25 (18). Top unlinked
target: ע"א 3213/97 (cited 5x) — natural #35 candidates.

## #32 — Wide-modal precedent edit

`precedent-edit-sheet.tsx`: ``<Sheet side="left">`` → centered
``<Dialog>`` with ``sm:max-w-4xl`` ``max-h-[90vh]`` ``overflow-y-auto``.
Component API unchanged so existing callers
(`/precedents/[id]/page.tsx`, `library-list-panel.tsx`) work as-is.
RTL preserved. Mobile falls back to near-full-width via shadcn default.

## #13 — 403/17 verification

`case_law e151fc25-...` (אהרון ברק - תכנית רחביה) already in perfect
shape after Stage A work: all metadata fields populated, 351 halachot
with avg_conf=0.864 (well above 0.78 threshold). No re-extraction
needed; closing task as verified.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

mcp-server/src/legal_mcp/services/db.py

@@ -875,6 +875,36 @@ CREATE UNIQUE INDEX IF NOT EXISTS uq_cases_number_proc
 """
 
 
+# ── V16: Internal citations graph (TaskMaster #34) ────────────────
+# Auto-extracted citation graph between Daphna's (and other internal_committee)
+# decisions. When an internal decision cites another committee decision in a
+# patterned way ("ונפנה ל…", "כפי שקבעתי…", "ראה החלטתי…"), the citation
+# extractor records the link here. ``cited_case_law_id`` is populated when the
+# cited case_number resolves to a row in ``case_law``; otherwise it stays NULL
+# and shows up in ``idx_pic_unlinked`` so the chair can decide whether to
+# upload the missing decision.
+SCHEMA_V16_SQL = """
+CREATE TABLE IF NOT EXISTS precedent_internal_citations (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    source_case_law_id UUID NOT NULL REFERENCES case_law(id) ON DELETE CASCADE,
+    cited_case_number TEXT NOT NULL,
+    cited_case_law_id UUID REFERENCES case_law(id) ON DELETE SET NULL,
+    match_context TEXT,
+    match_pattern TEXT,
+    confidence NUMERIC(3,2) DEFAULT 0.85,
+    created_at TIMESTAMPTZ DEFAULT NOW(),
+    UNIQUE (source_case_law_id, cited_case_number)
+);
+CREATE INDEX IF NOT EXISTS idx_pic_source
+    ON precedent_internal_citations(source_case_law_id);
+CREATE INDEX IF NOT EXISTS idx_pic_target
+    ON precedent_internal_citations(cited_case_law_id);
+CREATE INDEX IF NOT EXISTS idx_pic_unlinked
+    ON precedent_internal_citations(cited_case_number)
+    WHERE cited_case_law_id IS NULL;
+"""
+
+
 async def _run_schema_migrations(pool: asyncpg.Pool) -> None:
     async with pool.acquire() as conn:
         await conn.execute(SCHEMA_SQL)
@@ -893,7 +923,8 @@ async def _run_schema_migrations(pool: asyncpg.Pool) -> None:
         await conn.execute(SCHEMA_V13_SQL)
         await conn.execute(SCHEMA_V14_SQL)
         await conn.execute(SCHEMA_V15_SQL)
-    logger.info("Database schema initialized (v1-v15)")
+        await conn.execute(SCHEMA_V16_SQL)
+    logger.info("Database schema initialized (v1-v16)")
 
 
 async def init_schema() -> None: