feat: implement analyze command with arborist-metrics integration

Add `devtrail analyze [path]` for code complexity analysis using the
arborist-metrics crate. Supports cognitive + cyclomatic metrics with
--threshold, --output (text/json/markdown), and --top flags. Includes
10 integration tests and config.yml extension for threshold settings.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: montfort

CLAUDE.md

@@ -12,9 +12,10 @@ devtrail/
 ├── cli/                    # Rust CLI source code
 │   ├── src/
 │   │   ├── main.rs         # Entry point, command routing
-│   │   ├── commands/       # Subcommands: init, update, remove, status, repair, validate, compliance, metrics, audit, explore, about
+│   │   ├── commands/       # Subcommands: init, update, remove, status, repair, validate, compliance, metrics, analyze, audit, explore, about
 │   │   ├── tui/            # Terminal UI for `explore` (ratatui + crossterm)
-│   │   ├── config.rs       # DevTrailConfig, Checksums
+│   │   ├── analysis_engine.rs # Code complexity analysis (arborist-metrics)
+│   │   ├── config.rs       # DevTrailConfig, Checksums, ComplexityConfig
 │   │   ├── download.rs     # GitHub API, ZIP downloads
 │   │   ├── inject.rs       # Directive injection system
 │   │   ├── manifest.rs     # dist-manifest.yml parser
@@ -178,6 +179,7 @@ Users can now run `devtrail update-framework` to get the new version.
 | `devtrail validate [path]` | Validate documents for compliance and correctness |
 | `devtrail compliance [path]` | Check regulatory compliance (EU AI Act, ISO 42001, NIST) |
 | `devtrail metrics [path]` | Show governance metrics and documentation statistics |
+| `devtrail analyze [path]` | Analyze code complexity (cognitive + cyclomatic metrics) |
 | `devtrail audit [path]` | Generate audit trail reports with timeline and traceability |
 | `devtrail explore [path]` | Interactive TUI documentation browser |
 | `devtrail about` | Show version and license info |
@@ -196,7 +198,7 @@ cargo build --no-default-features  # Without TUI
 ### Test
 
 ```bash
-cargo test    # All 95 tests
+cargo test    # All 111 tests
 ```
 
 ### Feature Flags

README.md

@@ -103,6 +103,7 @@ Built-in CLI tools for governance:
 - **`devtrail validate`** — 13 validation rules for document correctness
 - **`devtrail compliance`** — Regulatory compliance scoring (EU AI Act, ISO 42001, NIST AI RMF)
 - **`devtrail metrics`** — Governance KPIs, review rates, risk distribution, trends
+- **`devtrail analyze`** — Code complexity analysis (cognitive + cyclomatic) via arborist-metrics
 - **`devtrail audit`** — Audit trail reports with timeline, traceability maps, and HTML export
 - **Pre-commit hooks** + **GitHub Actions** for CI/CD validation
 
@@ -164,6 +165,7 @@ Check installed versions with `devtrail status` or `devtrail about`.
 | `devtrail validate [path]` | Validate documents for compliance and correctness |
 | `devtrail compliance [path]` | Check regulatory compliance (EU AI Act, ISO 42001, NIST) |
 | `devtrail metrics [path]` | Show governance metrics and documentation statistics |
+| `devtrail analyze [path]` | Analyze code complexity (cognitive + cyclomatic metrics) |
 | `devtrail audit [path]` | Generate audit trail reports with timeline and traceability |
 | `devtrail explore [path]` | Browse documentation interactively in a TUI |
 | `devtrail about` | Show version and license info |

cli/Cargo.lock

@@ -35,10 +35,12 @@ tar = "0.4"
 ratatui = { version = "0.29", optional = true, default-features = false, features = ["crossterm"] }
 crossterm = { version = "0.28", optional = true }
 pulldown-cmark = { version = "0.12", optional = true }
+arborist-metrics = { version = "0.1", optional = true }
 
 [features]
-default = ["tui"]
+default = ["tui", "analyze"]
 tui = ["ratatui", "crossterm", "pulldown-cmark"]
+analyze = ["arborist-metrics"]
 
 [dev-dependencies]
 assert_cmd = "2"