feat(report): add report schema identity

CHANGELOG.md

@@ -7,6 +7,7 @@ All notable user-visible changes should be recorded here.
 ### Added
 
 - Added sanitized golden `report.md` / `report.json` regression fixtures to lock report contracts.
+- Added `schema` and `schema_version` fields to `report.json` so downstream tooling can identify the report artifact contract.
 - Expanded parser coverage for `Accepted publickey` and selected `pam_faillock` / `pam_sss` variants.
 - Added compact host-level summaries for multi-host reports.
 - Added optional CSV export for findings and warnings when explicitly requested.

docs/report-artifacts.md

@@ -18,6 +18,8 @@ Without `--csv`, LogLens does not create, overwrite, or delete existing CSV file
 The JSON report keeps parser observability visible next to findings:
 
 - `tool`
+- `schema`
+- `schema_version`
 - `input`
 - `input_mode`
 - `assume_year` for syslog-style input when a year is supplied
@@ -44,6 +46,11 @@ Finding objects contain `rule_id`, `rule`, `subject_kind`, `subject`, `grouping_
 
 Warning objects contain the original `line_number`, parser `category`, and parser `reason`.
 
+`schema` and `schema_version` identify the report artifact contract, not the
+application release. They are intended for downstream tooling that needs a
+stable way to reject incompatible report shapes. The current JSON contract is
+`loglens.report.v1` with `schema_version` set to `1`.
+
 Parser failure categories are stable reviewer-facing buckets for unsupported
 lines: `unknown_timestamp`, `unknown_program`,
 `known_program_unknown_message`, `malformed_source_ip`, and

src/report.cpp

@@ -637,6 +637,8 @@ std::string render_json_report(const ReportData& data) {
 
     output << "{\n";
     output << "  \"tool\": \"LogLens\",\n";
+    output << "  \"schema\": \"loglens.report.v1\",\n";
+    output << "  \"schema_version\": 1,\n";
     output << "  \"input\": \"" << escape_json(data.input_path.generic_string()) << "\",\n";
     output << "  \"input_mode\": \"" << to_string(data.parse_metadata.input_mode) << "\",\n";
     if (data.parse_metadata.assume_year.has_value()) {

tests/fixtures/report_contracts/journalctl_short_full/report.json

@@ -1,5 +1,7 @@
 {
   "tool": "LogLens",
+  "schema": "loglens.report.v1",
+  "schema_version": 1,
   "input": "tests/fixtures/report_contracts/journalctl_short_full/input.log",
   "input_mode": "journalctl_short_full",
   "timezone_present": true,

tests/fixtures/report_contracts/multi_host_journalctl_short_full/report.json

@@ -1,5 +1,7 @@
 {
   "tool": "LogLens",
+  "schema": "loglens.report.v1",
+  "schema_version": 1,
   "input": "tests/fixtures/report_contracts/multi_host_journalctl_short_full/input.log",
   "input_mode": "journalctl_short_full",
   "timezone_present": true,

tests/fixtures/report_contracts/multi_host_syslog_legacy/report.json

@@ -1,5 +1,7 @@
 {
   "tool": "LogLens",
+  "schema": "loglens.report.v1",
+  "schema_version": 1,
   "input": "tests/fixtures/report_contracts/multi_host_syslog_legacy/input.log",
   "input_mode": "syslog_legacy",
   "assume_year": 2026,

tests/fixtures/report_contracts/syslog_legacy/report.json

@@ -1,5 +1,7 @@
 {
   "tool": "LogLens",
+  "schema": "loglens.report.v1",
+  "schema_version": 1,
   "input": "tests/fixtures/report_contracts/syslog_legacy/input.log",
   "input_mode": "syslog_legacy",
   "assume_year": 2026,

tests/test_report.cpp

@@ -183,6 +183,15 @@ void test_json_finding_includes_explainability_fields() {
            "expected json finding to include evidence event ids");
 }
 
+void test_json_report_includes_schema_identity() {
+    const auto json = loglens::render_json_report(make_report_data());
+
+    expect(json.find("\"schema\": \"loglens.report.v1\"") != std::string::npos,
+           "expected json report to include schema identifier");
+    expect(json.find("\"schema_version\": 1") != std::string::npos,
+           "expected json report to include schema version");
+}
+
 void test_reports_include_total_input_line_count() {
     auto data = make_report_data();
     data.parser_quality.total_lines = 3;
@@ -349,6 +358,7 @@ int main() {
     test_markdown_table_cells_escape_user_controlled_values();
     test_json_escapes_generic_control_characters();
     test_json_finding_includes_explainability_fields();
+    test_json_report_includes_schema_identity();
     test_reports_include_total_input_line_count();
     test_csv_neutralizes_formula_like_fields();
     test_write_reports_fails_when_report_path_is_directory();

tests/test_report_contracts.cpp

@@ -138,6 +138,8 @@ std::vector<std::string> extract_json_contract_lines(const std::string& json) {
         }
 
         if (starts_with(line, "\"tool\": ")
+            || starts_with(line, "\"schema\": ")
+            || starts_with(line, "\"schema_version\": ")
             || starts_with(line, "\"input\": ")
             || starts_with(line, "\"input_mode\": ")
             || starts_with(line, "\"assume_year\": ")