fix(sql): recover CREATE FUNCTION/PROCEDURE from tree-sitter ERROR nodes (#1910)

tree-sitter-sql parses PL/pgSQL CREATE FUNCTION statements (OUT/INOUT
params, tagged dollar quotes, PERFORM/:= body statements) as ERROR
nodes, and the dispatch loop had no branch for them, so the functions
were silently dropped from the graph.

Handle ERROR nodes inside walk() (they can nest inside a merged
create_function during multi-statement error recovery) and dispatch
top-level ERROR statements to it. The branch regex-scans the raw node
text for every CREATE [OR REPLACE] FUNCTION/PROCEDURE, mirroring the
existing fb_proc_or_trigger and has_error fallbacks, with a name class
that keeps schema-qualified names (exposed.important_function) whole.
The PL/pgSQL body is not scanned for FROM/JOIN references to avoid
junk reads_from targets, and node ids match the clean create_function
branch so seen_ids dedups consistently.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

graphify/extractors/sql.py

@@ -191,6 +191,25 @@ def extract_sql(path: Path, content: str | bytes | None = None) -> dict:
                     tbl_nid = table_nids.get(tbl_name.lower()) or _make_id(stem, tbl_name)
                     _add_edge(trig_nid, tbl_nid, "triggers", line)
 
+        elif t == "ERROR":
+            # tree-sitter-sql cannot parse PL/pgSQL CREATE FUNCTION/PROCEDURE
+            # bodies (OUT/INOUT params, tagged dollar quotes, PERFORM, :=) and
+            # emits an ERROR node instead, silently dropping the object.
+            # Regex-scan the raw text as fallback, mirroring the
+            # fb_proc_or_trigger recovery below. One ERROR blob can swallow
+            # several statements, so scan for every CREATE in it. We deliberately
+            # do not scan the body for FROM/JOIN references: PL/pgSQL loop
+            # variables and locals would produce junk reads_from targets.
+            text = _read(node)
+            for m in re.finditer(
+                r"CREATE\s+(?:OR\s+REPLACE\s+)?(?:FUNCTION|PROCEDURE)\s+([\w$.]+)",
+                text, re.IGNORECASE,
+            ):
+                name = m.group(1)
+                m_line = line + text[: m.start()].count("\n")
+                nid = _make_id(stem, name)
+                _add_node(nid, f"{name}()", m_line)
+
         elif t == "fb_proc_or_trigger":
             text = _read(node)
             m = re.match(
@@ -249,7 +268,7 @@ def extract_sql(path: Path, content: str | bytes | None = None) -> dict:
         if stmt.type == "statement":
             for child in stmt.children:
                 walk(child)
-        elif stmt.type in ("fb_proc_or_trigger", "set_term", "declare_external_function"):
+        elif stmt.type in ("fb_proc_or_trigger", "set_term", "declare_external_function", "ERROR"):
             walk(stmt)
 
     # Global regex fallback: catch any REFERENCES missed due to ERROR nodes in the parse tree