Initial commit: Conflict Checker

Cross-discipline design-contradiction checker for construction drawing
sets. Standalone tool broken out from Iron_Bid; a pipeline stage may
later fold back into Iron_Bid.

Pipeline: PDF->images -> per-sheet assertion extraction -> deterministic
clustering by location -> per-cluster reasoning -> report.
Includes CLI (cli/run_check.py) and web UI (backend/main.py).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/email_sender.py

@@ -0,0 +1,123 @@
+"""
+email_sender.py - Sends a completion notification for a conflict check.
+
+Plain stdlib smtplib, all config from env (see config.py). Mirrors IronBid's
+graceful behavior: if SMTP is not configured, or a send fails, it logs and
+returns without ever crashing the pipeline.
+"""
+
+import os
+import ssl
+import smtplib
+from email.message import EmailMessage
+from typing import Dict, List, Optional
+
+from backend import config
+
+
+def _smtp_ready() -> bool:
+    return bool(config.SMTP_HOST and config.SMTP_USER and config.SMTP_PASSWORD)
+
+
+def _send(msg: EmailMessage) -> bool:
+    try:
+        if config.SMTP_USE_SSL:
+            ctx = ssl.create_default_context()
+            with smtplib.SMTP_SSL(config.SMTP_HOST, config.SMTP_PORT, context=ctx) as s:
+                s.login(config.SMTP_USER, config.SMTP_PASSWORD)
+                s.send_message(msg)
+        else:
+            with smtplib.SMTP(config.SMTP_HOST, config.SMTP_PORT) as s:
+                if config.SMTP_USE_TLS:
+                    s.starttls(context=ssl.create_default_context())
+                s.login(config.SMTP_USER, config.SMTP_PASSWORD)
+                s.send_message(msg)
+        return True
+    except Exception as e:
+        print(f"[Email] Failed to send: {e}")
+        return False
+
+
+def send_conflict_report(
+    recipient_email: str,
+    report: Dict,
+    results_url: str = "",
+    attachments: Optional[List[str]] = None,
+) -> bool:
+    """
+    Email the conflict-check summary to recipient_email, with the report files
+    attached. Returns True if sent, False if skipped/failed.
+    """
+    if not recipient_email:
+        return False
+    if not _smtp_ready():
+        print(f"[Email] SMTP not configured - skipping notification to {recipient_email}")
+        return False
+
+    s = report.get("summary", {})
+    source = report.get("source", "drawing set")
+    sev = s.get("by_severity", {})
+    found = s.get("conflicts_found", 0)
+
+    msg = EmailMessage()
+    msg["Subject"] = f"Conflict Checker - {source} - {found} conflict(s) found"
+    msg["From"] = config.SMTP_FROM or config.SMTP_USER
+    msg["To"] = recipient_email
+
+    lines = [
+        "Your conflict check is complete.",
+        "",
+        f"Drawing set:   {source}",
+        f"Sheets:        {s.get('sheets_analyzed', 0)}  ({', '.join(s.get('disciplines', [])) or 'none'})",
+        f"Facts checked: {s.get('assertions_extracted', 0)} across {s.get('clusters_checked', 0)} location clusters",
+        "",
+        "RESULT",
+        f"  Conflicts found: {found}",
+        f"    High:   {sev.get('high', 0)}",
+        f"    Medium: {sev.get('medium', 0)}",
+        f"    Low:    {sev.get('low', 0)}",
+    ]
+    by_stage = s.get("by_stage")
+    if by_stage:
+        lines += [
+            "",
+            "QAQC REVIEW",
+            f"  Full-set QAQC issues: {by_stage.get('qaqc', 0)}",
+            f"  Code / ADA issues:    {by_stage.get('code', 0)}",
+            f"  Constructability:     {by_stage.get('constructability', 0)}",
+            f"  Consolidated issues:  {by_stage.get('validated', 0)}",
+            f"  RFIs drafted:         {by_stage.get('rfis', 0)}",
+        ]
+    if s.get("cost_usd") is not None:
+        lines += ["", f"LLM cost: ${s['cost_usd']:.4f} over {s.get('llm_calls', 0)} calls"]
+    mu = s.get("models_used", {})
+    if mu:
+        lines += ["", "AI MODELS"]
+        if mu.get("vision"):
+            lines += [f"  Vision:     {', '.join(mu['vision'])}"]
+        if mu.get("text_local"):
+            lines += [f"  Text local: {', '.join(mu['text_local'])}"]
+        if mu.get("text_cloud"):
+            label = "Text cloud" if not mu.get("text_local") else "Text cloud (fallback)"
+            lines += [f"  {label}: {', '.join(mu['text_cloud'])}"]
+        if mu.get("fallback_count"):
+            lines += [f"  Local->cloud fallbacks: {mu['fallback_count']}"]
+    if results_url:
+        lines += ["", "VIEW FULL REPORT", f"  {results_url}"]
+    lines += ["", "Generated by Conflict Checker"]
+    msg.set_content("\n".join(lines))
+
+    for path in attachments or []:
+        if not path or not os.path.isfile(path):
+            continue
+        with open(path, "rb") as f:
+            data = f.read()
+        name = os.path.basename(path)
+        subtype = "json" if name.endswith(".json") else "plain"
+        maintype = "application" if name.endswith(".json") else "text"
+        msg.add_attachment(data, maintype=maintype, subtype=subtype, filename=name)
+
+    if _send(msg):
+        print(f"[Email] Sent conflict report to {recipient_email}")
+        return True
+    return False