Send the specific JetBrains IDE name for session tracking

Client-side follow-up from the [Scalable Approach for Adding New IDE Session Types RFC]() (lower priority than coder/vscode-coder#1044 since JetBrains IDEs are one vendor rather than many forks).

The plugin hardcodes `--usage-app=jetbrains` and `CODER_SSH_SESSION_TYPE=JetBrains` (`CoderCLIManager.kt`), and server-side process detection cannot tell PyCharm from GoLand, so every JetBrains IDE buckets under `jetbrains`.

Once the server accepts arbitrary app names (coder/coder#27410 → coder/coder#27412):

* Derive the product from the JetBrains platform API (e.g. `ApplicationInfo`/`ApplicationNamesInfo` product name) and send it through both mechanisms, e.g. `goland`, `pycharm`, `rustrover`; the server normalizes whatever is sent (lowercase, `-` → `_`)
* Same version-gating pattern as the VS Code extension: send a specific name only when the connected deployment is new enough, otherwise keep `jetbrains`
* Server-side family grouping keeps all of these under the JetBrains family in metric labels and legacy aggregates, so existing dashboards do not fragment

### Done when

- [ ] GoLand and PyCharm sessions are distinguishable in session counts on a new-enough deployment
- [ ] Older deployments still receive `jetbrains`

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🤖 Created by Coder Agents on behalf of @EhabY.

Start in CoderCLIManager.kt and inspect the JetBrains platform APIs mentioned in the issue, such as ApplicationInfo or ApplicationNamesInfo, for the product name. Compare the VS Code extension's version-gating pattern and trace both session-tracking mechanisms. Done means GoLand and PyCharm are distinguishable on new deployments while older deployments still receive jetbrains.

Written by the indexing model from the issue text.