rename project to MultiforaDB

Prose and benchmark tables use MultiforaDB; the binary, the CLI usage
line, the log-message prefix and the default database file use
multiforadb.

Two consequences worth noting:

- build.zig.zon's fingerprint is derived from the package name, so it
  had to change with it (Zig refuses to build otherwise). A consumer
  pinning this package by fingerprint needs updating.
- the default --db path is now multiforadb.log, and getCmdLineOpts
  reports it as dbpath. An existing mongo-lite.log has to be passed
  explicitly with --db.

The e2e harness abbreviated the old name as ML_; that is now MFDB_,
including the documented ML_BIN override (MFDB_BIN) and the scratch
file names. MD_ (mongod) is untouched.

compare-run.sh spawned the server by absolute path under a
sandbox/mongo-lite directory that no longer exists; that block already
runs from tests/e2e, so it uses a relative path now.

The archived reports under tests/e2e/results/ keep the old name: they
record what the old binary measured.

README.md

@@ -1,4 +1,4 @@
-# mongo-lite
+# MultiforaDB
 
 A lightweight, embedded MongoDB-compatible document database written in
 Zig 0.16. Like SQLite, it stores everything in a single file; unlike SQLite,
@@ -11,7 +11,7 @@ driver, PyMongo — connect over TCP and just work.
 zig build                # build the server
 zig build test           # run the unit test suite
 
-zig-out/bin/mongo-lite --port 27017 --db data.log --compact-threshold 256m
+zig-out/bin/multiforadb --port 27017 --db data.log --compact-threshold 256m
 
 # in another terminal:
 mongosh --port 27017
@@ -181,27 +181,27 @@ the `tests/e2e/big.js` harness (12-core/32 GB Mac):
 ## Performance vs MongoDB
 
 `tests/e2e/compare-run.sh` runs the same driver workload (1 GB, 65,536 ×
-16 KB docs, every write durable — mongo-lite fsyncs per command, mongod
+16 KB docs, every write durable — MultiforaDB fsyncs per command, mongod
 runs with `j: true`) against each server and prints a side-by-side table.
 With the ReleaseFast default build (MongoDB 8.3.7 on the same Mac):
 
-| benchmark | mongo-lite | mongodb | winner |
+| benchmark | MultiforaDB | mongodb | winner |
 |---|---|---|---|
-| insertOne (sequential) | 0.20 ms | 4.7 ms | **mongo-lite ×24** |
-| bulk insert (insertMany) | 752 MB/s | 744 MB/s | mongo-lite |
-| createIndex({k: 1}) | 67 ms | 76 ms | **mongo-lite** |
-| countDocuments({}) | 2.6 ms | 11.2 ms | **mongo-lite ×4** |
-| findOne({_id}) | 0.45 ms | 0.65 ms | **mongo-lite** |
-| findOne indexed | 0.54 ms | 4.6 ms | **mongo-lite ×8** |
+| insertOne (sequential) | 0.20 ms | 4.7 ms | **MultiforaDB ×24** |
+| bulk insert (insertMany) | 752 MB/s | 744 MB/s | MultiforaDB |
+| createIndex({k: 1}) | 67 ms | 76 ms | **MultiforaDB** |
+| countDocuments({}) | 2.6 ms | 11.2 ms | **MultiforaDB ×4** |
+| findOne({_id}) | 0.45 ms | 0.65 ms | **MultiforaDB** |
+| findOne indexed | 0.54 ms | 4.6 ms | **MultiforaDB ×8** |
 | range-scan count | 13.7 ms | 12.6 ms | mongodb ×1.1 |
 | sort + limit(20), on `_id` | 2.3 ms | 2.0 ms | mongodb ×1.1 |
 | sort + limit(20), indexed field | 1.0 ms | — | — |
-| aggregate $group | 8.1 ms | 12.3 ms | **mongo-lite** |
-| updateOne({_id}) | 0.15 ms | 0.19 ms | **mongo-lite** |
-| updateMany (65 docs) | 1.7 ms | 6.1 ms | **mongo-lite ×3.6** |
-| deleteOne + insert | 0.50 ms | 4.9 ms | **mongo-lite ×10** |
-| server RSS | 539 MB | 1.3 GB | **mongo-lite ×2.4** |
-| kill -9 → reopen | 0.8 s | 1.3 s | **mongo-lite** |
+| aggregate $group | 8.1 ms | 12.3 ms | **MultiforaDB** |
+| updateOne({_id}) | 0.15 ms | 0.19 ms | **MultiforaDB** |
+| updateMany (65 docs) | 1.7 ms | 6.1 ms | **MultiforaDB ×3.6** |
+| deleteOne + insert | 0.50 ms | 4.9 ms | **MultiforaDB ×10** |
+| server RSS | 539 MB | 1.3 GB | **MultiforaDB ×2.4** |
+| kill -9 → reopen | 0.8 s | 1.3 s | **MultiforaDB** |
 | db on disk | 97 MB | 91 MB | mongodb |
 
 The engine now holds every document as canonical BSON bytes in a