feat: [#242] enhance provision command output with connection details

[josecelano]

Summary

Enhances the provision command to display SSH connection details after successful infrastructure provisioning. This provides users with immediate, actionable information to connect to their newly provisioned instances.

Closes #242

Changes

New Features

• Connection Details Display: After successful provisioning, users now see:
  • Instance IP address
  • SSH port
  • SSH private key path
  • SSH username
  • Ready-to-copy SSH connection command

Architecture

Implements a clean MVC pattern with proper DDD layering:

• View Layer (src/presentation/views/commands/provision/):

  • ConnectionDetailsView: Renders formatted output
  • ConnectionDetailsData: DTO for connection information
  • Follows presentation → domain dependency (DDD compliant)

• Controller (src/presentation/controllers/provision/handler.rs):

  • Orchestrates functional pipeline: Environment<Provisioned> → ConnectionDetailsData → String → stdout
  • Uses From trait for clean DTO conversion
  • Proper error propagation with ? operator

Code Quality

• Law of Demeter: Uses environment convenience methods (ssh_port(), ssh_username())
• Functional Style: Pipeline composition eliminates intermediate variables
• String Templates: Uses format! macro for efficient rendering
• Error Handling: Proper Result propagation throughout the stack
• Missing IP Handling: Gracefully displays warning (not error) if IP unavailable

Testing

• 5 unit tests for view rendering:

  • Complete details with IP
  • Warning display when IP missing
  • Custom SSH ports
  • Absolute path handling
  • Path preservation

• 4 controller tests (existing):

  • Invalid environment name
  • Empty environment name
  • Nonexistent environment
  • Valid environment name

All tests passing ✅

Output Example

Instance Connection Details:
  IP Address:        10.140.190.171
  SSH Port:          22
  SSH Private Key:   /home/user/.ssh/deploy_key
  SSH Username:      torrust

Connect using:
  ssh -i /home/user/.ssh/deploy_key torrust@10.140.190.171 -p 22

Technical Decisions

1. From Trait Placement: Implemented in presentation layer (not domain) to maintain DDD - domain should not depend on presentation DTOs

2. Output Channel: Uses ProgressReporter::result() to route to stdout (not stderr) since connection details are final command results, not progress information

3. View Separation: Created new commands/ directory structure for command-specific views, maintaining clear organization

4. Functional Pipeline: Used functional composition for clarity and to eliminate intermediate variables

Quality Checks

All pre-commit checks passed:

• ✅ Linting (markdown, yaml, toml, cspell, clippy, rustfmt, shellcheck)
• ✅ Dependencies (cargo machete)
• ✅ Tests (unit + integration + E2E)
• ✅ Documentation (cargo doc)

Related Documentation

• User Guide: docs/user-guide/commands/
• Architecture: docs/codebase-architecture.md
• DDD Layer Placement: docs/contributing/ddd-layer-placement.md
• Output Handling: docs/contributing/output-handling.md

[josecelano]

ACK 24c7c97