* master: read the writable-volumes cap from master.toml
-maxWritableVolumes becomes the master.max_writable_volumes config key,
so the new master limit is set the same way as other master options
instead of a flag wired into every command that embeds a master.
* master: name the writable cap master.max_writable_volumes_per_layout
The cap applies per volume layout (collection + replica placement + ttl +
disk type), so the key names its scope instead of reading as a global cap.
* master: keep an embedder's MaxWritableVolumes when the key is unset
NewMasterServer overwrote option.MaxWritableVolumes with the viper
value, which reads as 0 whenever master.toml omits the key, silently
dropping a cap a Go caller supplied through MasterOption. Seed the
default from the option instead so the field survives an absent key;
an explicit config entry still wins.
* master: drop stray nested-checkout gitlinks
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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---------
Co-authored-by: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
