Pick 0.5.15 changes to arrow-rs crates

[AnIrishDuck]

Looks like we missed #64 and #66 .

I've gone over everything else (and had goose + Opus 4.5 double check in parallel). These are the only missing links after the prior round of cherry picks (#62):

c43fe71 (HEAD -> fmurphy/arrow-rs-0.5.15, origin/fmurphy/arrow-rs-0.5.15) Pick 0.5.15 changes to arrow-rs crates
3e5021c (origin/main, origin/HEAD, main) Add back sample testing (#71)
73bca23 Complete merge of plateau-server-arrow-rs to main (#70)
dfe0729 Complete merge of plateau-catalog-arrow-rs into main (#68)
a434f85 (tag: v0.5.15) Bump version to 0.5.15
8aa2dd1 Add CatalogRetention, mount point retention (#66)
2bdf7bb (tag: v0.5.14) Bump version to 0.5.14
d01a55b Fix recovery / recovered paths and double counting (#65)
f2c23c2 (tag: v0.5.13) Bump version to 0.5.13
16a3f99 Add gauges for cold topics (#64)
f8e8542 Better error reporting on common client and server failures (#63)
165062b Cherry-pick 0.5.12 changes to arrow-rs crates (#62)

d01a55b was actually a reverse merge error, the recovered fix never made it back to the main crates. And f8e8542 happened before we forked the server code:

* 73bca23 Complete merge of plateau-server-arrow-rs to main (#70)
| * 0ae125c (origin/fmurphy/server-arrow-rs) Migrate plateau-server-arrow-rs to arrow-rs
| | * 8bf1676 (origin/goose/server, goose/server) Migrate plateau-server-arrow-rs to arrow-rs
| |/  
| * 81933e7 (origin/fmurphy/server-arrow-rs-base, goose/server-base) Copy plateau-server => plateau-server-arrow-rs
|/  
* dfe0729 Complete merge of plateau-catalog-arrow-rs into main (#68)

[... snip ...]

* | f2c23c2 (tag: v0.5.13) Bump version to 0.5.13
* | 16a3f99 Add gauges for cold topics (#64)
* | f8e8542 Better error reporting on common client and server failures (#63)
* ```