Fix max_tokens to 16K for Opus (API limit is 32K, need room for thinking)

block-yod max_tokens reduced from 32K to 16K — the API returned
"max_tokens: 32768 > 32000" error. With thinking enabled, the actual
limit for output is lower. 16K is sufficient for discussion blocks.

Also: extractor.py now supports .md files (was missing, blocked
Beit HaKerem upload).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

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

@@ -51,7 +51,7 @@ BLOCK_CONFIG = {
     "block-zayin":{"index": 7, "title": "טענות הצדדים", "gen_type": "paraphrase", "temp": 0.1, "model": "sonnet", "max_tokens": 16384},
     "block-chet": {"index": 8, "title": "הליכים", "gen_type": "reproduction", "temp": 0, "model": "sonnet", "max_tokens": 8192},
     "block-tet":  {"index": 9, "title": "תכניות חלות", "gen_type": "guided-synthesis", "temp": 0.2, "model": "opus", "max_tokens": 16384},
-    "block-yod":  {"index": 10, "title": "דיון והכרעה", "gen_type": "rhetorical-construction", "temp": 0.4, "model": "opus", "max_tokens": 32768},
+    "block-yod":  {"index": 10, "title": "דיון והכרעה", "gen_type": "rhetorical-construction", "temp": 0.4, "model": "opus", "max_tokens": 16384},
     "block-yod-alef": {"index": 11, "title": "סיכום", "gen_type": "paraphrase", "temp": 0.1, "model": "sonnet", "max_tokens": 8192},
     "block-yod-bet":  {"index": 12, "title": "חתימות", "gen_type": "template-fill", "temp": 0, "model": "script"},
 }