> :robot: **Generated with the help of an LLM**, reviewed and approved by me before posting. Blocked by #3606535 (closed), which carries the interface change that declares 2.0.x. ## Problem/Motivation Defects found while auditing the configuration forms, the dashboard and the export surfaces for 2.0.0. None of them breaks compatibility, and none belonged in a patch release. ### Configuration and dashboard 1. `ForensicRouteAnalysisManageForm.php:162-163` falls back with `??`, but the decoded subject always carries both keys. The fallback is dead code, and an external request with no Drupal route renders two empty cells. 2. `DatabaseObserverCleanupHandler` calls `deleteOlderThan()` without a limit, so `cleanup_batch_limit` does not bound the age-based purge of that table. The setting description says it bounds every handler. 3. `report_limit` in the database observer settings is written by the form and read by nothing. The report page uses a hardcoded 50. 4. `strict_fallback` in the report settings changes no observable behaviour. Its only effect is avoiding a duplicate path that `array_unique()` removes anyway. 5. The OpenTelemetry settings form lets an operator enable the exporter without an endpoint. `isAvailable()` then returns false, the subscriber returns silently, and nothing is logged. 6. `TechnicalInsightsController::export()` answers 204 for an unknown dataset key, the same as for a valid dataset with no rows. A typo in the URL yields an empty file rather than a 404. 7. The config schema declares `client_ip_mode`, `user_agent_mode`, `headers_mode`, `query_mode` and `body_mode` as free strings. A configuration imported from a file passes with any value. 8. 140 of 4499 `page_cache` rows with status `UNCACHEABLE (no cacheability)` carry a null `request_id`. ### Drupal 12 compatibility 9. 24 calls pass an integer to `fetchAll()` or `fetchAllAssoc()`. Both arguments are deprecated in Drupal 11.2 and **removed in Drupal 12**. 10. Six Kernel and Functional test classes do not declare `#[RunTestsInSeparateProcesses]`. In Drupal 12 that **throws**, it does not warn. ### Window functions 11. The dashboard ranks endpoint samples with `ROW_NUMBER() OVER (PARTITION BY ...)`. MySQL 5.7 has no window functions and Drupal 10 still allows it, so the query fails on a database this module declares support for. `docs/installation.md` promised any database supported by Drupal core. ### Two write paths 12. The runtime environment snapshot is copied into the payload of every cache tag invalidation. Nothing reads it back. On the measured dataset it was 41984 bytes across 41 rows, 58 percent of all payload bytes. 13. `/admin/reports/native-observability/prometheus` is an admin route behind a permission, but it runs the same controller as the unauthenticated scrape path and demands a bearer token as well. It answers 401 to the administrators it exists for. No menu links it. 14. The export settings form warns that the endpoint "is publicly accessible without authentication" whenever no token is set. With no token and no explicit opt-in the controller answers 403 to everyone. A second warning a few lines below states the opposite, and both render together. 15. `ObservabilityReportDocumentBuilder` reuses `$title` for the conclusion section, so the document `<title>` reads "Conclusion". A browser saving the printable report as PDF takes the filename from there. ### Documentation 16. The documentation carries no version marker. With `1.0.x`, `1.1.x` and `2.0.x` all alive, a reader cannot tell which release the pages describe. ### Published overhead 17. The report publishes an overhead percentage summed from four hardcoded constants, printed as "Estimated overhead: 10%". No constant in it was ever measured, and the number describes no installation. Removing it leaves the report with nothing to say about the module's cost, so a real measurement has to take its place. 18. Uninstalling the module leaves its private tempstore entries behind. Drupal expires them on a schedule but never drops a collection when its owner is uninstalled, so per-user rows stay in `key_value_expire` until the last one lapses. A full uninstall of the family left 22567 rows: 22540 from Execution, 26 from Report, 1 from the overhead batch. ## Steps to reproduce 1. Add a forensic subject for an outbound HTTP target that resolves to no Drupal route, then open the management form. Two cells render empty. 2. Set `cleanup_batch_limit` to 10, leave more than 10 expired rows in `native_observability_database_query`, and run cleanup. Every expired row is deleted in one statement. 3. Grep the module for `report_limit` and for `strict_fallback`. Only the forms write them. 4. Enable the OpenTelemetry exporter with an empty endpoint and issue a request. No span is sent and no message is logged. 5. Request `/admin/reports/native-observability/export/does_not_exist`. The answer is 204. 6. Run the test suite and read the deprecation list. `fetchAll()` and `RunTestsInSeparateProcesses` are both there. 7. Open `/admin/reports/native-observability/prometheus` as an administrator holding `access native observability prometheus endpoint`. The answer is 401 and the page is blank. 8. Clear the Prometheus bearer token and open the export settings form. Two warnings render, and they contradict each other. 9. Generate a report preview, open the printable HTML, and read the browser tab. It says "Conclusion". 10. Generate a report with the overhead section included. It prints a percentage no code on the site ever measured. 11. Uninstall the whole family, then count rows in `key_value_expire` whose collection starts with `tempstore.private.native_observability`. They are still there. ## Proposed resolution Test for the empty string rather than for a missing key, and use the label the other view already shows for a route-less subject. Pass the batch limit to the age purge. Make the report page read `report_limit`. Give `strict_fallback` an effect. Require the endpoint when the exporter is enabled. Answer 404 for an unknown dataset. Add `constraints: Choice` to the five capture mode keys. Replace every integer fetch mode with `fetchAssoc()` in a loop, and add the missing attribute to the six test classes. Do not use the `FetchAs` enum core suggests: it does not exist in Drupal 10, which this module still supports. Probe the connected server for window functions rather than reading the Drupal version, and rank in PHP where the server cannot do it. Report the fallback through `hook_requirements` instead of blocking the install. Stop copying the environment snapshot into the payload. Serve the Prometheus admin route from a method that trusts the permission the router already enforced. Remove the warning that contradicts the accurate one. Give the conclusion section its own variable. State the branch the documentation describes, and add a page covering the move from 1.1.x. Delete the estimator and measure instead. Time a workload with capture on and with capture off, in paired blocks, alternating which side runs first. Report the median of the paired differences, checked with an exact two-sided sign test, and run an OFF/OFF control pass so a delta counts as `measurable` only when it clears the machine's own noise floor and p <= 0.05. Offer the same protocol from `drush no:overhead:measure` and from an admin form. Give the report three disclosure states, hidden, declared by the document author and measured on this server, and make the label naming the source impossible to turn off. Clear the module's own tempstore collections on uninstall. ## Measured, not inferred Defect 8 is **not reproducible** on the current code. The `page_cache` table now holds zero rows without a `request_id`. The rows that remained were written during the 1.1.0 upgrade test, before the middleware guard landed. No further work is planned for it. The two ranking paths were compared on live data and return the same row ids per endpoint, reading 34 rows where the SQL path reads 17. Defect 18 was found by a release acceptance run, not by reading the code: a full uninstall of the twelve modules left 22567 tempstore rows behind, and the fix is proven by a second uninstall that leaves none.