Updates tooling branding and configuration to use the jpm name and related defaults.
- Aligns CLI messaging and docs to reference jpm instead of previous name.
- Updates registry entry defaults (repository URL, destination path).
- Changes temporary working directory prefix used during fetch operations.
- Adds project SDK configuration entries for the IDE.
- Adjusts README usage instructions to match the renamed commands.
These changes keep tooling, docs, and runtime behavior consistent with the jpm namespace.
Christoph Brandau
58bc6523fb