Refactor monolithic main.rs into modular architecture with 93 tests

Split 5,393-line main.rs into 4 module trees:
- commands/ (review, git, pr, eval, smart-review, misc)
- parsing/ (LLM response parsing, smart review response parsing)
- output/ (formatting: JSON, Patch, Markdown, Smart Review output)
- review/ (pipeline, filters, feedback, context helpers, rule helpers)

main.rs is now a 364-line thin shell with CLI struct and dispatch only.
Added 70+ new unit tests across all modules (93 total, up from ~23).
Zero warnings, clean clippy.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: haasonsaas

src/commands/eval.rs

@@ -0,0 +1,175 @@
+use anyhow::Result;
+use clap::Subcommand;
+use std::path::PathBuf;
+use tracing::info;
+
+use crate::adapters;
+use crate::config;
+use crate::core;
+use crate::output::OutputFormat;
+use crate::review::review_diff_content_with_repo;
+
+#[derive(Subcommand)]
+pub enum GitCommands {
+    Uncommitted,
+    Staged,
+    Branch {
+        #[arg(help = "Base branch/ref (defaults to repo default)")]
+        base: Option<String>,
+    },
+    Suggest,
+    PrTitle,
+}
+
+pub async fn git_command(
+    command: GitCommands,
+    config: config::Config,
+    format: OutputFormat,
+) -> Result<()> {
+    let git = core::GitIntegration::new(".")?;
+
+    let diff_content = match command {
+        GitCommands::Uncommitted => {
+            info!("Analyzing uncommitted changes");
+            git.get_uncommitted_diff()?
+        }
+        GitCommands::Staged => {
+            info!("Analyzing staged changes");
+            git.get_staged_diff()?
+        }
+        GitCommands::Branch { base } => {
+            let base_branch = base.unwrap_or_else(|| {
+                git.get_default_branch()
+                    .unwrap_or_else(|_| "main".to_string())
+            });
+            info!("Analyzing changes from branch: {}", base_branch);
+            git.get_branch_diff(&base_branch)?
+        }
+        GitCommands::Suggest => {
+            return suggest_commit_message(config).await;
+        }
+        GitCommands::PrTitle => {
+            return suggest_pr_title(config).await;
+        }
+    };
+
+    if diff_content.is_empty() {
+        println!("No changes found");
+        return Ok(());
+    }
+
+    let repo_root = git.workdir().unwrap_or_else(|| PathBuf::from("."));
+    review_diff_content_with_repo(&diff_content, config, format, &repo_root).await
+}
+
+async fn suggest_commit_message(config: config::Config) -> Result<()> {
+    let git = core::GitIntegration::new(".")?;
+    let diff_content = git.get_staged_diff()?;
+
+    if diff_content.is_empty() {
+        println!("No staged changes found. Stage your changes with 'git add' first.");
+        return Ok(());
+    }
+
+    let model_config = adapters::llm::ModelConfig {
+        model_name: config.model.clone(),
+        api_key: config.api_key.clone(),
+        base_url: config.base_url.clone(),
+        temperature: config.temperature,
+        max_tokens: config.max_tokens,
+        openai_use_responses: config.openai_use_responses,
+    };
+
+    let adapter = adapters::llm::create_adapter(&model_config)?;
+
+    let (system_prompt, user_prompt) =
+        core::CommitPromptBuilder::build_commit_prompt(&diff_content);
+
+    let request = adapters::llm::LLMRequest {
+        system_prompt,
+        user_prompt,
+        temperature: Some(0.3),
+        max_tokens: Some(500),
+    };
+
+    let response = adapter.complete(request).await?;
+    let commit_message = core::CommitPromptBuilder::extract_commit_message(&response.content);
+
+    println!("\nSuggested commit message:");
+    println!("{}", commit_message);
+
+    if commit_message.len() > 72 {
+        println!(
+            "\n⚠️  Warning: Commit message exceeds 72 characters ({})",
+            commit_message.len()
+        );
+    }
+
+    Ok(())
+}
+
+async fn suggest_pr_title(config: config::Config) -> Result<()> {
+    let git = core::GitIntegration::new(".")?;
+    let base_branch = git
+        .get_default_branch()
+        .unwrap_or_else(|_| "main".to_string());
+    let diff_content = git.get_branch_diff(&base_branch)?;
+
+    if diff_content.is_empty() {
+        println!("No changes found compared to {} branch.", base_branch);
+        return Ok(());
+    }
+
+    let model_config = adapters::llm::ModelConfig {
+        model_name: config.model.clone(),
+        api_key: config.api_key.clone(),
+        base_url: config.base_url.clone(),
+        temperature: config.temperature,
+        max_tokens: config.max_tokens,
+        openai_use_responses: config.openai_use_responses,
+    };
+
+    let adapter = adapters::llm::create_adapter(&model_config)?;
+
+    let (system_prompt, user_prompt) =
+        core::CommitPromptBuilder::build_pr_title_prompt(&diff_content);
+
+    let request = adapters::llm::LLMRequest {
+        system_prompt,
+        user_prompt,
+        temperature: Some(0.3),
+        max_tokens: Some(200),
+    };
+
+    let response = adapter.complete(request).await?;
+
+    // Extract title from response
+    let title = if let Some(start) = response.content.find("<title>") {
+        if let Some(end) = response.content.find("</title>") {
+            response.content[start + 7..end].trim().to_string()
+        } else {
+            response.content.trim().to_string()
+        }
+    } else {
+        // Fallback: take the first non-empty line
+        response
+            .content
+            .lines()
+            .find(|line| !line.trim().is_empty())
+            .unwrap_or("")
+            .trim()
+            .to_string()
+    };
+
+    println!("\nSuggested PR title:");
+    println!("{}", title);
+
+    if title.len() > 65 {
+        println!(
+            "\n⚠️  Warning: PR title exceeds 65 characters ({})",
+            title.len()
+        );
+    }
+
+    Ok(())
+}