Support categories/sections in generic.toml for better organization

[Th0rgal]

Problem

The `generic.toml` file contains 27+ checks in a flat list with no organizational structure. As users add custom checks, it becomes hard to navigate and maintain. A user reported that they tried adding category separators but it crashed the plugin (likely because the parser treats every top-level key as a check).

Root cause: `ConfigsManager.loadGenericChecks()` iterates all top-level TOML keys and tries to parse each one as a `GenericCheck`. There's no way to add organizational metadata without it being parsed as a check.

Suggested approach

Add an optional `category` field to each check entry:

[labymod_v1]
actions = ["alert"]
channels = ["LABYMOD"]
name = "Labymod v1"
category = "clients"

[forge]
actions = ["alert"]
channels = ["MC|Brand", "minecraft:brand"]
message_has = "forge"
name = "Forge"
category = "loaders"

[my_custom_check]
actions = ["alert"]
channels = ["custom:channel"]
name = "My Custom Check"
category = "custom"

Changes needed:

1. Add a `category` field to `GenericCheck.java` (default to `"other"` if not specified)
2. Parse the field in `ConfigsManager.loadGenericChecks()`
3. Optionally group checks by category in the `/hs inv` and `/hs check` output

This is backward-compatible: existing configs without `category` fields will still work.

Relevant files

• `hackedserver-core/src/main/resources/generic.toml`
• `hackedserver-core/src/main/java/org/hackedserver/core/config/GenericCheck.java`
• `hackedserver-core/src/main/java/org/hackedserver/core/config/ConfigsManager.java`