chore(vendor): update vendored libenderlog to v0.0.3

Dated record timestamps, per-sink timestamp format, and archive names
that keep the extension last (<stem>.<timestamp>.<ext>).

third_party/libenderlog/README.md

@@ -23,8 +23,8 @@ engine, not on a logging framework.
   (for tests and in-game consoles) ship; `sink` is a small interface.
 - **File output with archiving.** `file_sink` writes to a file and, on open,
   moves an existing log aside to a timestamped archive, so a run never appends
-  onto a previous run's log. It can also rotate by size and bound how many
-  archives are kept.
+  onto a previous run's log. It can also rotate by size, bound how many archives
+  are kept, and format both the record timestamp and the archive names.
 - **No stacktrace? No problem.** Where `<stacktrace>` is missing (libc++, and
   therefore every cross target), the module still compiles and records still
   carry their call site — they simply have no stack.
@@ -104,7 +104,7 @@ auto main() -> int {
 Example output:
 
 ```
-[11:32:18] ERROR    example: a body left the world  (examples/main.cpp:8)
+[2026-10-01 11:32:18] ERROR    example: a body left the world  (examples/main.cpp:8)
     #0  simulate_one_step (examples/main.cpp:8)
     #1  main (examples/main.cpp:20)
     #2  <unknown>
@@ -137,14 +137,21 @@ auto sink = log::add_file_sink("enderlog.log", {.max_file_size = 64 * 1024, .max
 ```
 
 - **No appending onto a previous run.** On open, an existing non-empty
-  `enderlog.log` is renamed to `enderlog.<YYYYmmdd-HHMMSS>.log` before the new
-  file is created, so every run gets its own file and the previous run's log is
-  preserved. A leftover empty file is simply replaced.
+  `enderlog.log` is renamed to `enderlog.<timestamp>.log` before the new file is
+  created, so every run gets its own file and the previous run's log is
+  preserved. The timestamp is inserted before the extension, which stays last
+  (`.log` when the active file has none). A leftover empty file is simply
+  replaced.
 - `file_options::max_file_size` (0 disables) rotates the active file mid-run the
   same way, and never archives an empty file. `file_options::max_archives`
   (0 keeps all) deletes the oldest archives beyond the limit.
 - `file_options::flush_each_record` (on by default) flushes after every record so
   a crash keeps the tail.
+- `file_options::timestamp_format` (chrono syntax, default `%Y-%m-%d %H:%M:%S`)
+  controls the timestamp on each record's header line;
+  `file_options::archive_time_format` (chrono syntax, default `%Y%m%d-%H%M%S`)
+  controls the timestamp inserted into archive names. A chrono format string must
+  begin with `%` (e.g. `%Y-%m-%d_%H%M%S`).
 - `add_file_sink` adds the sink to the global logger and returns it; `path()` and
   `archives()` expose what it wrote. The `file_sink` class can also be used
   directly and installed with `set_sinks`.