feat(http): segmented parallel download via HTTP Range; bump 0.3.0

aria2-style multi-connection downloads. download_to_file_parallel()
probes with Range: bytes=0-0, then splits the file into segments
fetched concurrently into a pre-allocated file by a worker pool
pulling from a shared segment index:

- maxConnectionsPerFile caps concurrent workers (-x)
- maxSegments sets the split count (-s); 0 ties it to the connection
  count, preserving the pre-feature behavior
- minSegmentBytes sets the smallest split worth making (--min-split-size)
- interrupted segments resume mid-range on retry (2 retries each)
- falls back to the sequential path when the server ignores Range,
  the resource is empty (416), or the file is too small to split
- 206 responses are validated (Content-Range start/total, no chunked
  framing) so a misbehaving server cannot corrupt the output
- progress callbacks stay monotonic across worker threads

All existing API is unchanged; default config (maxConnectionsPerFile=1)
behaves exactly like before.

Author: FarnaHerry

mcpp.lock

@@ -5,5 +5,5 @@ version = 2
 namespace = "compat"
 version = "3.6.1"
 source  = "index+compat@3.6.1"
-hash    = "fnv1a:83dea67ac1379be3"
+hash    = "fnv1a:bb700e69e973ccd0"
 

mcpp.toml

@@ -1,8 +1,12 @@
+# Local fork of mcpplibs/tinyhttps 0.2.9 with segmented parallel downloads
+# (HTTP Range multi-connection, aria2-style). All existing API is unchanged;
+# the new surface is HttpClientConfig.maxConnectionsPerFile and
+# HttpClient::download_to_file_parallel().
 [package]
 namespace   = "mcpplibs"
 name        = "tinyhttps"
-version     = "0.2.9"
-description = "Minimal C++23 HTTP/HTTPS client with SSE streaming support"
+version     = "0.3.0"
+description = "Minimal C++23 HTTP/HTTPS client (fork: + Range segmented parallel download)"
 license     = "Apache-2.0"
 repo        = "https://github.com/mcpplibs/tinyhttps"