…uites

Previously every suite scaffolded into a fixed <repo>/temp* directory, which
forced hand-assigned unique names per file (to avoid collisions) and a
.gitignore entry. Generate projects in a fresh Directory.systemTemp.createTemp
instead: collisions are impossible by construction going forward, nothing
lands in the repo tree, and it matches the cwd-independence the generated
projects already have (their path deps are absolute via SERVERPOD_HOME).

The generated server now uses embedded PostgreSQL

Drop the --concurrency=1 that the suite needed only for the shared Docker
database; the generated projects now use embedded PostgreSQL, so the suites
isolate themselves and can run at the default concurrency.

…tor bundles

- Replace Zonky extension-less binaries with Serverpod bundles (PG + PostGIS + pgvector) from GitHub Releases.
- Add a BinaryArtifact seam; BinaryStore generic over it.
- Add ServerpodBundleArtifact + .tar.xz extraction; keep ZonkyArtifact for back-compat/tests.
- Supervisor sets PROJ_LIB to bundle share/proj so PostGIS transforms survive cache relocation.
- Validate prefetch(target:) against published suffixes; post-extract shape check before caching.
- README: shipped PostGIS 3.5.4 + pgvector 0.8.3; add artifact URL/platform-mapping test.

…s + CI

- tool/build_postgres builds PG 16.13 + PostGIS 3.5.4 + pgvector 0.8.3 via zig cc/c++ into a relocatable .tar.xz.
- GitHub Actions matrix builds per-runner, publishes an embedded-postgres-v<bom> release (PG_VERSION from the tag).
- zigshim adapts macOS flags zig mishandles (-bundle, libc++ headers, UBSan, headerpad).
- zigshim: -Wno-unknown-warning-option on real compiles only; honors ZIG_VERSION for anyzig pinning.
- build-core force-keeps backend symbols so extensions resolve at load.
- package.sh archives STAGE at tar root (extract resolves bin/postgres); codesign arm64-only.
- Windows scaffold: x86_64-windows-gnu under MSYS2, geo .dll beside postgres.exe (UNVALIDATED).
- macOS x64 verified end-to-end.

- BinarySource { auto, download, build }; set via EmbeddedPostgresOptions.binarySource or SERVERPOD_PG_SOURCE.
- auto falls back to a local build only on a 404 (not transient errors); build forces it; download is unchanged.
- BundleBuilder runs tool/build_postgres/build-all.sh (package-relative or SERVERPOD_PG_BUILD_DIR), streams output.
- BinaryStore.ensure takes (source, builder); widens claim stale/timeout windows when a build may run.
- BinaryFetchException carries statusCode so auto can distinguish 404.
- Lets CI build on normal runs (force, no publish); publish stays tag-triggered.

…le in CI

- From-source relocatable PG 16.13 + PostGIS 3.5.4 + pgvector 0.8.3 bundle, downloaded per-platform at runtime.
- No Docker to provision a DB for tests or local dev.
- Toolchain: Apple clang on macOS (zig-clang 21 miscompiled the backend), zig cc glibc-2.28 on Linux, mingw gcc on Win.
- Static GEOS/PROJ/json-c; PostGIS -j1 (rtpostgis.sql.tmp race); raster/protobuf/address_standardizer/NLS off.
- Windows: export GEOS/PROJ DLL symbols, force-include <cstdint> for PROJ, materialize PostGIS symlinks as files.
- macOS: rewrite install_names/rpaths to @loader_path (re-sign on arm64).
- CI: build each bundle once in a seed job, hand to test jobs via artifact; restore-only cache + gated save.
- Run embedded-PG integration suites on Linux, macOS, Windows.

…t lock on start

- A postmaster mid-shutdown removes postmaster.pid early but holds the Unix socket lock until it fully exits.
- A launch then passed the pid liveness check but crashed: "lock file ... already exists".
- Port-retry only covered TcpTransport, so the Unix-socket case had no recovery.
- On start, read run/.s.PGSQL.<port>.lock; if it names a live PID, wait for exit (reuse waitForPidExit).

- add ubuntu-24.04-arm + macos-15 legs to seed_embedded_pg and the two embedded
  test matrices, so every <os>-<arch> ServerpodBundleArtifact serves (Abi.current)
  is built/tested, not just x64
- the embedded-PG test jobs are server-side `dart test` (no Flutter), and Flutter
  ships no Linux-arm64 SDK, so swap flutter-action -> setup-dart on them