feat: add two-instance compare review UI (Phase 2)

- outline_sync.py: write compare results to /tmp/compare_results.json
  with full doc maps for parent-chain lookup during copy operations
- webui.py: /review page with remote-only, local-only, conflict tables;
  /review/content endpoint to fetch doc text from either instance;
  /review/apply endpoint for copy_to_local, copy_to_remote, keep_remote,
  keep_local, skip actions; "Compare Instances" button on dashboard;
  "Review Differences" link shown after compare completes
- entrypoint.sh: include local block in generated settings.json
- docker-compose.yml: pass LOCAL_OUTLINE_URL/TOKEN/HOST env vars
- deploy.yml: write LOCAL_* secrets to .env file

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

outline_sync.py

@@ -128,7 +128,7 @@ def sanitize_name(name: str, max_len: int = 200) -> str:
 
 class OutlineSync:
 
-    def __init__(self, base_url: str, api_token: str, vault_dir: Path):
+    def __init__(self, base_url: str, api_token: str, vault_dir: Path, host_header: str = ""):
         self.base_url  = base_url.rstrip("/")
         self.api_token = api_token
         self.vault_dir = Path(vault_dir)
@@ -146,6 +146,8 @@ class OutlineSync:
             "Authorization": f"Bearer {self.api_token}",
             "Content-Type":  "application/json",
         }
+        if host_header:
+            self.headers["Host"] = host_header
 
         self._doc_cache: Dict[str, Dict] = {}
         self.stats = {"collections": 0, "documents": 0, "errors": 0}
@@ -701,7 +703,7 @@ class OutlineSync:
             self._collect_docs_keyed(tree, coll["name"], out)
         return out
 
-    def cmd_compare(self, local_url: str, local_token: str) -> bool:
+    def cmd_compare(self, local_url: str, local_token: str, local_host: str = "") -> bool:
         """
         Fetch both the remote and local Outline instances and print a diff report.
         No writes to either instance.
@@ -721,7 +723,7 @@ class OutlineSync:
         print(f"  → {len(remote_docs)} documents\n")
 
         print("Fetching local instance (outline-web)...")
-        local_client = OutlineSync(local_url, local_token, self.vault_dir)
+        local_client = OutlineSync(local_url, local_token, self.vault_dir, host_header=local_host)
         if not local_client.health_check(label="local"):
             print("✗  Cannot reach local Outline API — aborting.")
             return False
@@ -791,6 +793,47 @@ class OutlineSync:
                 print(f"  ~ {key}")
                 print(f"      remote: {r_ts}  local: {l_ts}")
 
+        # Write structured results for the review UI
+        results_data = {
+            "timestamp": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
+            "remote_url":  self.base_url,
+            "local_url":   local_url,
+            "local_host":  local_host,
+            "summary": {
+                "in_sync":     in_sync,
+                "remote_only": remote_only,
+                "local_only":  local_only,
+                "conflicts":   conflicts,
+            },
+            "entries": {
+                "remote_only": [
+                    {"key": k, "title": remote_docs[k]["title"],
+                     "id": remote_docs[k]["id"], "ts": remote_docs[k]["updatedAt"]}
+                    for k in results["remote_only"]
+                ],
+                "local_only": [
+                    {"key": k, "title": local_docs[k]["title"],
+                     "id": local_docs[k]["id"], "ts": local_docs[k]["updatedAt"]}
+                    for k in results["local_only"]
+                ],
+                "conflicts": [
+                    {"key": key, "title": r["title"],
+                     "remote_id": r["id"], "remote_ts": r["updatedAt"],
+                     "local_id":  l["id"], "local_ts":  l["updatedAt"]}
+                    for key, r, l in results["conflict"]
+                ],
+            },
+            # Full doc maps for parent-chain lookup during copy
+            "all_remote": remote_docs,
+            "all_local":  local_docs,
+        }
+        try:
+            Path("/tmp/compare_results.json").write_text(
+                json.dumps(results_data), encoding="utf-8"
+            )
+        except Exception as exc:
+            logger.warning("Could not write compare results: %s", exc)
+
         return True
 
     # ── Commands ──────────────────────────────────────────────────────────────
@@ -885,6 +928,7 @@ def parse_args() -> argparse.Namespace:
     p.add_argument("--token",       help="Remote API token (overrides settings.source.token)")
     p.add_argument("--local-url",   help="Local Outline API URL (overrides settings.local.url)")
     p.add_argument("--local-token", help="Local API token (overrides settings.local.token)")
+    p.add_argument("--local-host",  help="Host header for local instance (overrides settings.local.host)")
     p.add_argument(
         "-v", "--verbose",
         action="count",
@@ -931,13 +975,14 @@ def main() -> None:
     elif args.command == "compare":
         local_url   = args.local_url   or local.get("url")
         local_token = args.local_token or local.get("token")
+        local_host  = args.local_host  or local.get("host", "")
         if not local_url or not local_token:
             logger.error(
                 "Missing local API URL or token — set local.url and local.token "
                 "in settings.json, or pass --local-url / --local-token."
             )
             sys.exit(1)
-        ok = sync.cmd_compare(local_url, local_token)
+        ok = sync.cmd_compare(local_url, local_token, local_host)
     else:
         ok = False
     sys.exit(0 if ok else 1)