feat: IMAP mail sync with thread-to-contact matching (PRD §6.1)

Real IMAP connection via imapflow library:
- Connects to IMAP server (IMAPFlow, TLS on port 993)
- Fetches recent messages (configurable limit, default 20)
- Extracts: from, fromEmail, subject, date, snippet (200 chars)
- Thread-to-contact matching (PRD §6.1):
  1. Match sender email against persons table
  2. If no person match, extract domain and match against company.website
  3. Returns matchedCompany + matchedPerson for each email
- Audit-logged (action: crm.mailsync:imap)
- Zod validated (host, port, user, password, folder, limit)
- 502 on IMAP connection failure with detail
- 400 on validation failure

Tested: invalid creds → 502 'IMAP connection failed', missing host → 400

skills/pdf/env_setup/env_check.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+# Lightweight environment check for PDF skill.
+# Exit 0 = all OK, exit 1 = missing dependencies.
+# Also resolves and exports PDF_SKILL_DIR and FONT_DIR.
+# Usage: source env_check.sh  (preferred, exports vars to caller)
+#    or: bash env_check.sh [--quiet]
+QUIET=false; [ "${1:-}" = "--quiet" ] && QUIET=true
+FAIL=0
+check() { local desc="$1"; shift; if ! "$@" &>/dev/null; then $QUIET || echo "MISSING: $desc"; FAIL=1; fi; }
+
+# ── Resolve PDF_SKILL_DIR & FONT_DIR ──
+_ENV_CHECK_DIR="$(cd "$(dirname "${BASH_SOURCE[0]:-$0}")" && pwd)"
+PDF_SKILL_DIR="$(cd "$_ENV_CHECK_DIR/.." && pwd)"
+export PDF_SKILL_DIR
+
+if [ "$(uname -s)" = "Darwin" ]; then
+    FONT_DIR="${HOME}/Library/Fonts"
+else
+    FONT_DIR="/usr/share/fonts"
+fi
+export FONT_DIR
+
+check "python3"    command -v python3
+check "node"       command -v node
+check "pikepdf"    python3 -c "import pikepdf"
+check "pdfplumber" python3 -c "import pdfplumber"
+check "pypdf"      python3 -c "import pypdf"
+check "reportlab"  python3 -c "import reportlab"
+check "PyMuPDF"    python3 -c "import fitz"
+check "playwright" node -e "require('playwright')"
+
+# LaTeX engine (tectonic) — needed for Academic pipeline
+if [ -x "$PDF_SKILL_DIR/scripts/tectonic" ]; then
+    : # bundled binary OK
+elif command -v tectonic &>/dev/null; then
+    : # system tectonic OK
+else
+    $QUIET || echo "MISSING: tectonic (needed for LaTeX/Academic PDFs)"
+    FAIL=1
+fi
+
+# Font check: verify CJK fonts are available
+if command -v fc-list &>/dev/null; then
+    fc-list :lang=zh 2>/dev/null | grep -qi "noto\|simhei\|wenquanyi" || { $QUIET || echo "MISSING: CJK fonts"; FAIL=1; }
+fi
+
+$QUIET || echo "PDF_SKILL_DIR=$PDF_SKILL_DIR"
+$QUIET || echo "FONT_DIR=$FONT_DIR"
+return $FAIL 2>/dev/null || exit $FAIL