[EdmondDantes]

Closes #362.

An HTTP/1 file body that failed or came up short left the connection open, so the next response was read as the rest of the body.

• Both HTTP/1 on_done callbacks honour the engine's status; a failed body marks the framing lost, so http_request_finalize neither keeps the connection nor serves a pipelined request.
• Plaintext sendfile reports bytes_sent < body_length as a failure (php-async completes a sendfile at EOF with status 0 and a short count).
• A body sized from a stale open-file cache entry evicts it, so the next request is sized from the file.
• The engine takes its defer timer before arming the caller; a refusal returns SEND_FILE_REFUSED and the request is answered whole (static: the synchronous path; sendFile(): 500) instead of completing inside the HTTP/1 parser.
• --enable-fault-injection compiles libfiu fault points and _http_fault_* hooks; the Linux debug CI leg enables it.

Needs true-async/php-async#308 (merged as 1521d69): Windows TransmitFile now reports a short transfer, and Darwin/FreeBSD wait out EAGAIN instead of cutting a 2 MiB body at about 1 MB.

Evidence: h1/065 (stale cache, plaintext) red 5 of 5 on main with the pipelined 200 glued after 4096 of 2097152 bytes, h1/068 the same over TLS, h1/066 and h1/067 through fault points red 3 of 3; all green on Linux, macOS and Windows CI. Local suite 520 of 546 passed, 25 skipped; the one failure is core/018's known log-ring overflow under -j4 (plan item 13), passing alone.

Mutants: S2, hand 10 by 28.2: 9 killed, 1 survived (fault_hooks.c name-length bound, now killed by core/083), 0 not run; base eaa2d57

[github-actions]

Coverage

Total lines: 83.70% → 83.83% (+0.14 pp)

File	Baseline	Current	Δ	Touched
src/core/fault_hooks.c	0.00%	100.00%	+100.00 pp	●
src/core/http_connection.c	83.64%	83.82%	+0.18 pp	●
src/core/http_connection.h	81.82%	81.82%	+0.00 pp	●
src/core/http_connection_tls.c	76.01%	76.26%	+0.25 pp
src/core/tls_layer.c	77.17%	77.69%	+0.52 pp
src/http1/http1_sendfile.c	73.20%	77.78%	+4.58 pp	●
src/http3/http3_listener.c	76.61%	76.76%	+0.15 pp
src/http_send_file.c	82.47%	82.47%	+0.00 pp	●
src/http_server.c	95.20%	95.24%	+0.04 pp	●
src/http_server_class.c	75.99%	75.95%	-0.04 pp
src/http_server_config.c	92.58%	92.52%	-0.06 pp
src/send_file.c	87.17%	87.50%	+0.33 pp	●
src/static/http_static.c	89.12%	89.12%	+0.00 pp	●
src/static/http_static_cache.c	69.82%	80.68%	+10.86 pp	●
src/websocket/ws_session.c	89.71%	89.89%	+0.18 pp