Add multi-root bundle support across the toolchain:
- `compile`: Accept multiple definition names via `-x NAME` (repeatable or
comma-separated). Exports all requested definitions as named roots in a
single bundle. Defaults to "main" when no names are given.
- `export`: Accept comma-separated hashes in the positional argument and
multiple `-n`/`names` flags. Exports all resolved roots in one bundle.
- Server: Add `GET /bundle/roots?n=...&h=...` endpoint that resolves
multiple stored-term names and/or raw Merkle hashes, returning a single
bundle containing all of them as roots.
- Wire: Export `defaultExportNames` helper for generating default export
names when none are supplied.
- Drop `cereal` dependency from `tricu.cabal` (no longer used).
Introduces a read-only HTTP server (WAI/Warp) backed by the content
store, exposing three bundle-export endpoints:
- GET /bundle/name/:name — export by stored term name
- GET /bundle/hash/:hash — export by full Merkle hash
- GET /terms — plain-text listing (debug)
Also adds `tricu server` (aka `--serve`) CLI mode, move `resolveExportTarget` /
`namesForHash` / `looksLikeHash` out of `Main.hs` into `ContentStore.hs`,
and cleans up unused exports and imports across `FileEval.hs` and `Wire.hs`.
