feat: wire --agent flag in command handlers and add Retrieve command

Task 5: Wire --agent in main.rs match arms for Analyze, Security,
Dependencies, Vulnerabilities, and Optimize commands. Each agent path
forces JSON output, passes through compression pipeline via
handle_agent_output helper, and stores full data for retrieval.

Task 6: Refactor handle_vulnerabilities to return Result<String>
so the agent path can capture JSON output for compression.

Add Retrieve command handling with --list, latest resolution,
filtered retrieval, and error reporting as structured JSON.

Update suppress_update_banner to also suppress for --agent mode
and Retrieve commands. Add Retrieve to telemetry command mapping.

Update lib.rs patterns to ignore new agent field on all commands
and add Retrieve arm (unreachable, handled in main.rs).

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

Author: 2 people

src/lib.rs

@@ -36,6 +36,7 @@ pub async fn run_command(
             display,
             only,
             color_scheme,
+            agent: _,
         } => {
             match handlers::handle_analyze(path, json, detailed, display, only, color_scheme) {
                 Ok(_output) => Ok(()), // The output was already printed by display_analysis_with_return
@@ -54,7 +55,7 @@ pub async fn run_command(
         } => handlers::handle_generate(
             path, output, dockerfile, compose, terraform, all, dry_run, force,
         ),
-        Commands::Validate { path, types, fix } => handlers::handle_validate(path, types, fix),
+        Commands::Validate { path, types, fix, agent: _ } => handlers::handle_validate(path, types, fix),
         Commands::Support {
             languages,
             frameworks,
@@ -67,6 +68,7 @@ pub async fn run_command(
             prod_only,
             dev_only,
             format,
+            agent: _,
         } => handlers::handle_dependencies(
             path,
             licenses,
@@ -82,7 +84,8 @@ pub async fn run_command(
             severity,
             format,
             output,
-        } => handlers::handle_vulnerabilities(path, severity, format, output).await,
+            agent: _,
+        } => handlers::handle_vulnerabilities(path, severity, format, output).await.map(|_| ()),
         Commands::Security {
             path,
             mode,
@@ -95,6 +98,7 @@ pub async fn run_command(
             format,
             output,
             fail_on_findings,
+            agent: _,
         } => {
             handlers::handle_security(
                 path,
@@ -133,6 +137,7 @@ pub async fn run_command(
             min_confidence,
             cloud_provider,
             region,
+            agent: _,
         } => {
             let format_str = match format {
                 cli::OutputFormat::Table => "table",
@@ -708,6 +713,10 @@ pub async fn run_command(
             agent::run_agent_server(&project_path, provider_type, model, &host, port).await?;
             Ok(())
         }
+        Commands::Retrieve { .. } => {
+            // Retrieve commands are handled in main.rs directly
+            unreachable!("Retrieve commands should be handled in main.rs")
+        }
         Commands::Deploy { .. } => {
             // Deploy commands are handled in main.rs directly
             unreachable!("Deploy commands should be handled in main.rs")