Feature plan: Step 1 · Step 2 · Step 3 · Step 4

Stage 1 - Platform aware manual setup guidance

• Changes: Extended the startup recovery message with PATH-first guidance, bounded Ubuntu 24.04/APT recognition, manual PHP 8.3 CLI/SQLite/mbstring instructions, privilege explanation, and generic fallback. Added an internal Bash helper that parses release fields without executing them; expanded README setup recovery. Grouped the four plans and updated the index.

• Verification: bash -n v3 scripts/php_setup_guidance.sh, existing bash tests/missing_php_startup_test.sh, and git diff --check passed. Direct ./v3 start </dev/null on this missing-PHP Ubuntu host returned exit 1 with supported instructions. Supported, older-release, duplicate-ID, and absent-file fixtures selected expected advice. Official Ubuntu package references in Step 3 confirm the recipe family; locally extracted package contents include pdo_sqlite.so and mbstring.so.

• Notes: Guidance only prints commands; it does not install, prompt, modify PATH/profiles, or retry. Server source remains unchanged. The separate dependency checklist remains uncommitted and outside feature commits. Deployment, system package installation, and migrations are not applicable to manual guidance.

Stage 2 - Detection failures and recovery verification

• Changes: Extended the standalone launcher test with quoted release fixtures, unsupported distributions/releases/kernels, duplicate/missing/malformed fields, read failure, kernel detection failure, missing APT, piped invocation, and installer stand-ins that record any unexpected execution. Retained all original forwarding/help checks.

• Verification: bash tests/missing_php_startup_test.sh, bash -n v3 scripts/php_setup_guidance.sh tests/missing_php_startup_test.sh, and git diff --check passed. Piped startup exited with guidance and no installation marker. Restoring the extracted temporary PHP runtime and running startup with a numeric port, quiet mode, and log path containing spaces yielded HTTP 200 for /assets/site.css; the server and temporary request state were cleaned up. All relative feature-plan links resolve.

• Notes: The smoke test proves actual server startup and asset serving, not dynamic application data configuration. Fixture tests call the internal helper; actual launcher tests cover wiring and missing-PHP/available-PHP behavior. No system packages were installed. Full PHP application tests, deployment, migrations, and external services are not required for this guidance-only runtime change.