Allow `clan templates list` to function outside a clan.
Currently when bootstrapping a clan and trying to list the templates
it fails as follows:
```
Traceback (most recent call last):
File "/nix/store/pkrsr8zr90bps1fwrl8n74zbb9g038b8-clan-cli/bin/.clan-wrapped", line 9, in <module>
sys.exit(main())
~~~~^^
File "/nix/store/pkrsr8zr90bps1fwrl8n74zbb9g038b8-clan-cli/lib/python3.13/site-packages/clan_cli/cli.py", line 516, in main
args.func(args)
~~~~~~~~~^^^^^^
File "/nix/store/pkrsr8zr90bps1fwrl8n74zbb9g038b8-clan-cli/lib/python3.13/site-packages/clan_cli/templates/list.py", line 11, in list_command
templates = list_templates(args.flake)
File "/nix/store/pkrsr8zr90bps1fwrl8n74zbb9g038b8-clan-cli/lib/python3.13/site-packages/clan_lib/templates/__init__.py", line 20, in list_templates
custom_templates = flake.select("clanInternals.inventoryClass.templatesPerSource")
^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'select'
```
With the change we get the following output:
```
Available 'clan' templates
├── <builtin>
│ ├── default: Initialize a new clan flake
│ ├── flake-parts: Flake-parts
│ └── minimal: for clans managed via (G)UI
Available 'disko' templates
├── <builtin>
│ └── single-disk: A simple ext4 disk with a single partition
Available 'machine' templates
├── <builtin>
│ ├── flash-installer: Initialize a new flash-installer machine
│ └── new-machine: Initialize a new machine
```
Allowing to check for available templates without needing to have a
clan, which improves the bootstrapping experience.
- Replace Tor-specific implementation with generic SOCKS5 proxy support
- Change `tor_socks` boolean to `socks_port` and `socks_wrapper` parameters
- Move Tor functionality to clan_lib.network.tor submodule
- Add connection context managers to NetworkTechnologyBase
- Improve network abstraction with proper remote() and connection() methods
- Update all callers to use new SOCKS5 proxy interface
- Fix network ping command to properly handle connection contexts
This allows for more flexible proxy configurations beyond just Tor,
while maintaining backward compatibility for Tor usage.
When creating a new clan, the key selection now looks like this:
```
Found existing admin keys on this machine:
1: type: AGE
pubkey: age1xyz...
source: /home/grmpf/.config/sops/age/keys.txt
2: type: PGP
pubkey: abc...
source: SOPS_PGP_FP
Select keys to use (comma-separated list of numbers, or leave empty to select all):
```
This is achieved by adding a `source` attribute to `SopsKey`.
This should better be fixed with types. It should be possible to initialize a flake from a Path, making it very clear that a path `foo` is meant and not a remote flake called `foo`
Fix common command flags registering.
Register the common command flags before triggering autocomplete,
that way we can use the flags in the autocompletions themselves.
Previously, paths like /nix/store/hash-file.nix:123 were incorrectly
treated as pure store paths and wrapped in {"outPath": ...}, breaking
the cache. This fix:
- Adds helper functions to properly detect and handle store references
- Distinguishes between pure store paths and paths with metadata (line numbers)
- Supports multiple store references in a single string
- Handles custom NIX_STORE_DIR correctly
- Ensures existence checks work for all store references
Also fixes test_cache_gc to delete NIX_REMOTE for proper local store testing.
When running for example `clan networks list` we now get a reasonable
error message, instead of:
```
Traceback (most recent call last):
File "/nix/store/8ygq8bfxqydk2917mmg32wy9wb0qzzzd-clan-cli/bin/.clan-wrapped", line 9, in <module>
sys.exit(main())
~~~~^^
File "/nix/store/8ygq8bfxqydk2917mmg32wy9wb0qzzzd-clan-cli/lib/python3.13/site-packages/clan_cli/cli.py", line 516, in main
args.func(args)
~~~~~~~~~^^^^^^
File "/nix/store/8ygq8bfxqydk2917mmg32wy9wb0qzzzd-clan-cli/lib/python3.13/site-packages/clan_cli/network/list.py", line 12, in list_command
networks = networks_from_flake(flake)
File "/nix/store/8ygq8bfxqydk2917mmg32wy9wb0qzzzd-clan-cli/lib/python3.13/site-packages/clan_lib/network/network.py", line 106, in networks_from_flake
networks_ = flake.select("clan.exports.instances.*.networking")
^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'select'
```
