ZigBase 0.2.0

Fixed

• Provisioning no longer leaks at shutdown: applySpecs and runMigrations
  now wrap all internal allocations in a short-lived arena (backed by the
  caller's allocator), so intermediate allocations from topoOrder,
  collections.create / ddl.quoteIdent, schema.indexesToJson, and the
  prov: migration-name string are all freed before the call returns. The
  long-lived gpa accumulates nothing during startup provisioning.
• Reserved field names in comptime .collections are rejected at compile
  time: declaring a field whose name is reserved by the engine (id,
  created, updated, email, username, passwordHash, tokenKey,
  verified) now produces a clear @compileError at build time rather than an
  opaque validation failure at startup.

Added

• Static file serving: root-path fallback with four comptime modes — runtime
  --serve-static <dir> flag (default), .disabled, comptime-hardcoded .dir, or
  assets fully .embedded in the binary via the new embedStaticDir build helper
  in build.zig. Embedded mode computes a CRC32 content ETag at build time and
  handles If-None-Match/304 itself. Dir mode (--serve-static or comptime .dir)
  delegates caching to facil.io's sendFile (ETag, Last-Modified,
  Cache-Control: max-age=3600, 304). All modes add X-Content-Type-Options: nosniff
  and lexical traversal protection (.., backslash, NUL). Static misses return
  plain-text 404; /api/* misses keep the JSON envelope.
• Example frontends: all three examples now ship an Astro + React-islands
  frontend (one per static mode: blog = runtime flag, golfsim = hardcoded dir,
  plugins = embedded). Blog and golfsim also gain comptime .collections schemas so
  the examples provision themselves at startup.