fix(parser): unquote TOML keys and section headers

Apache Airflow's `.cherry_picker.toml` uses TOML's quoted-key form:

    "check_sha" = "..."

`parseTOML` was reading the LHS as the raw text including the literal
quotes. The TomlStructureDetector then emitted node IDs like
`toml:.cherry_picker.toml:"check_sha"` while the CONTAINS edges (and
any downstream lookup) referenced different shapes — Kuzu's BulkLoad
aborted with:

    Copy exception: Unable to find primary key value
    "toml:.cherry_picker.toml:""check_sha"""

Bug was symmetric for `["quoted-section"]` headers. Fix both: call
the existing `unquote` helper on the key/section before storing.

Regression tests added in structured_test.go (new file).

End-to-end: `codeiq enrich ~/projects/polyglot-bench/airflow` now
exits 0 (was exit 2): 95k nodes, 246k edges, 165 services loaded.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: aksOps

go/internal/parser/structured.go

@@ -162,7 +162,7 @@ func parseTOML(source []byte) ParsedEnvelope {
 			continue
 		}
 		if strings.HasPrefix(raw, "[") && strings.HasSuffix(raw, "]") {
-			section := strings.TrimSpace(raw[1 : len(raw)-1])
+			section := unquote(strings.TrimSpace(raw[1 : len(raw)-1]))
 			currentSection = section
 			// Walk into a nested map; only create the top-level section in
 			// data — nested namespacing is preserved by the dotted key.
@@ -176,7 +176,7 @@ func parseTOML(source []byte) ParsedEnvelope {
 		if eq <= 0 {
 			continue
 		}
-		key := strings.TrimSpace(raw[:eq])
+		key := unquote(strings.TrimSpace(raw[:eq]))
 		val := strings.TrimSpace(raw[eq+1:])
 		val = unquote(val)
 		if currentSection == "" {

go/internal/parser/structured_test.go

@@ -0,0 +1,60 @@
+package parser
+
+import (
+	"testing"
+)
+
+func TestParseTOMLUnquotesKeys(t *testing.T) {
+	// `.cherry_picker.toml` in apache/airflow has `"check_sha" = "..."` —
+	// a quoted top-level key. Pre-fix the key string included the literal
+	// quotes which propagated into node IDs like
+	// `toml:.cherry_picker.toml:"check_sha"`, and CONTAINS edges then
+	// referenced PKs that the bulk-load couldn't resolve.
+	src := []byte(`team = "apache"
+repo = "airflow"
+"check_sha" = "abc123"
+'literal_key' = "single-quoted"
+`)
+	env := parseTOML(src)
+	data, ok := env["data"].(map[string]any)
+	if !ok {
+		t.Fatalf("envelope missing data map: %#v", env)
+	}
+	for k, want := range map[string]string{
+		"team":        "apache",
+		"repo":        "airflow",
+		"check_sha":   "abc123",
+		"literal_key": "single-quoted",
+	} {
+		got, ok := data[k].(string)
+		if !ok {
+			t.Errorf("key %q missing or non-string: %#v", k, data[k])
+			continue
+		}
+		if got != want {
+			t.Errorf("data[%q] = %q, want %q", k, got, want)
+		}
+	}
+	// Negative: a quoted form must NOT appear as its own key.
+	for _, badKey := range []string{`"check_sha"`, `'literal_key'`} {
+		if _, exists := data[badKey]; exists {
+			t.Errorf("data still has quote-bearing key %q — unquote not applied", badKey)
+		}
+	}
+}
+
+func TestParseTOMLUnquotesSectionHeaders(t *testing.T) {
+	// Less common in practice, but TOML spec allows `["foo.bar"]` quoted
+	// section headers. Same fix applies — unquote before using as map key.
+	src := []byte(`["quoted-section"]
+inner = "v"
+`)
+	env := parseTOML(src)
+	data := env["data"].(map[string]any)
+	if _, ok := data["quoted-section"]; !ok {
+		t.Errorf("missing top-level section 'quoted-section': %#v", data)
+	}
+	if _, ok := data[`"quoted-section"`]; ok {
+		t.Errorf("section header retained literal quotes — unquote not applied")
+	}
+}