smaller things:

- raise exception if user uses non-absolute paths for _local_ repositories. also for restic binary.
- raise warning if repository types are identical (there are some scenarios where this makes sense, but alert the user)

- timestamps aren't actually timezone aware, we should fix this
```
❯ uv run restic-replica
==============================
  restic-replica 0.1.1.dev0+b1f94cc
==============================
Program start @ 2025/09/19 15:59:14                <-------------- no +0100 offset. Boo.
Checking access to source repository
Checking access to destination repository
Starting copy of snapshots from source to destination repository

snapshot 7776c55f of [/etc/hosts] at 2025-09-19 15:58:42.197667192 +0100 BST by nathan@oracca.local
  copy started, this may take a while...
[0:00] 100.00%  2 / 2 packs copied

snapshot 7b7e51ce saved
Finished copying snapshots
```



bigger things

- support path/host filtering of snapshots. Could just support those for all restic commands actually.
- optionally init the repositories? (future enh)
- environment commands: set environment variables using commands, for safety. 
  - Basically in the event of the system being compromised, the remote repository should not necessarily be.
- cross replication/sync
- more robust handling of missing sections in the config file. So long as there's a "source" and "destination" section it should just work?
- support for specifying config file path via cli.
- tabular output of the snapshots to be copied
- reasoning why snapshots to be copied were selected by the filter.
- a better way of handling environment variables, seriously. Maybe if tried to avoid them wherever possible this would work better? I think in terms of auth, we probably need to know which variables need to be present for the copy op, and only filter those. Future enh though.


WONTIMPLEMENT:
- (this is impossible) if chunker params are different across src/tgt, warn? how would we detect this.