ad2ac21 docs: [#349] document JSON output format for create command (Jose Celano)
afa7ef9 feat: [#349] add JSON output format support to create command (Jose Celano)
2ecb391 refactor: [#349] apply Strategy Pattern for output formats (SOLID) (Jose Celano)
7ce64b0 feat: [#349] add global --output-format argument (Phase 1) (Jose Celano)
67c10ff refactor: [#349] extract view layer for create command (Phase 0) (Jose Celano)

Pull request description:

  ## Summary

  Implements issue #349 - Adds machine-readable JSON output format to the `create environment` command, enabling automation workflows and CI/CD integration.

  ## Changes

  ### Architecture (5 Phases)

  **Phase 0: View Layer Extraction (67c10ff)**
  - Extracted view layer for create command following MVC pattern
  - Created `EnvironmentDetailsData` DTO and `EnvironmentDetailsView`
  - Aligned with existing provision/list/show command architecture

  **Phase 1: Global OutputFormat Argument (7ce64b0)**
  - Added `OutputFormat` enum (Text | Json) with clap integration
  - Added `--output-format` global CLI argument
  - Extended `GlobalArgs` and `ExecutionContext` with format support

  **Phase 2: Strategy Pattern Implementation (2ecb391)**
  - Separated TextView and JsonView implementations
  - Applied SOLID principles with Strategy Pattern
  - Added `Serialize` derive to EnvironmentDetailsData

  **Phase 3: Format Switching (afa7ef9)**
  - Wired output_format through ExecutionContext → Router → Controller
  - Implemented format switching with match expression
  - Added OutputFormatting error variant with detailed help

  **Phase 4: Documentation (ad2ac21)**
  - Added comprehensive "Output Formats" section to user guide
  - Documented JSON schema with field descriptions
  - Added 8+ automation examples (Shell, CI/CD, Python, multi-env)
  - Explained stdout/stderr channel separation

  ### Features

  ✅ **Two Output Formats**:
  - **Text** (default): Human-readable numbered list with progress indicators
  - **JSON**: Machine-readable structured data for automation

  ✅ **JSON Output Schema**:
  ```json
  {
    "environment_name": "my-env",
    "instance_name": "torrust-tracker-vm-my-env",
    "data_dir": "./data/my-env",
    "build_dir": "./build/my-env",
    "created_at": "2026-02-16T13:38:02.446056727Z"
  }
  ```

  ✅ **CLI Usage**:
  ```bash
  # Default text output
  torrust-tracker-deployer create environment --env-file config.json

  # JSON output for automation
  torrust-tracker-deployer create environment --env-file config.json --output-format json

  # Short form
  torrust-tracker-deployer create environment --env-file config.json -o json
  ```

  ### Quality Assurance

  - ✅ All 2230 unit tests pass
  - ✅ All 394 doctests pass
  - ✅ All linters pass (clippy, rustfmt, markdown, yaml, toml, cspell, shellcheck)
  - ✅ Pre-commit checks pass
  - ✅ E2E testing completed:
    - Default text output verified
    - JSON output validated with jq
    - Error handling tested
    - Channel separation confirmed (stdout/stderr)
  - ✅ No unused dependencies (cargo-machete clean)

  ### Documentation

  - User guide updated with comprehensive examples
  - JSON schema documented with field descriptions
  - Automation examples for Shell, CI/CD, Python
  - Output channel separation explained
  - Usage guidelines included

  ## Testing

  ### Manual Verification

  ```bash
  # Text output (default)
  ./target/release/torrust-tracker-deployer create environment \
    --env-file envs/test.json

  # JSON output
  ./target/release/torrust-tracker-deployer create environment \
    --env-file envs/test.json \
    --output-format json

  # JSON validation with jq
  ./target/release/torrust-tracker-deployer create environment \
    --env-file envs/test.json \
    -o json \
    --log-output file-only | jq .
  ```

  ### Automation Example

  ```bash
  # Extract environment details
  DATA_DIR=$(./target/release/torrust-tracker-deployer create environment \
    --env-file config.json \
    -o json \
    --log-output file-only | jq -r '.data_dir')
  ```

  ## Related

  - Closes #349
  - Part of Epic #348 - Add JSON output format support
  - Roadmap Section 12.1

  ## Breaking Changes

  None. This is a backward-compatible addition. Default behavior (text output) is preserved.

  ## Future Work

  This implementation provides the foundation for adding JSON output to other commands:
  - provision (#350)
  - show (#351)
  - list (#352)
  - status (#353)

ACKs for top commit:
  josecelano:
    ACK ad2ac21

Tree-SHA512: 47677046a60e5da16b0195c9f35c5109b020a4f715b4e23eb3a3acad70fd96198bbda64ff8b240626db5015e205031a8d6a5b6c2ce51e4748bf4206b64913529