rewrite planoai CLI in Rust

Add crates/plano-cli/ as a full Rust rewrite of the Python CLI.
Binary name: planoai. All subcommands ported: up, down, build,
logs, cli-agent, trace, init. Config validation and Tera template
rendering replace the Python config_generator. CI updated to use
cargo test/build instead of Python test jobs.

crates/plano-cli/src/commands/build.rs

@@ -0,0 +1,105 @@
+use std::process::Command;
+
+use anyhow::{bail, Result};
+
+use crate::consts::plano_docker_image;
+use crate::utils::{find_repo_root, print_cli_header};
+
+pub async fn run(docker: bool) -> Result<()> {
+    let dim = console::Style::new().dim();
+    let red = console::Style::new().red();
+    let bold = console::Style::new().bold();
+
+    if !docker {
+        print_cli_header();
+
+        let repo_root = find_repo_root().ok_or_else(|| {
+            anyhow::anyhow!(
+                "Could not find repository root. Make sure you're inside the plano repository."
+            )
+        })?;
+
+        let crates_dir = repo_root.join("crates");
+
+        // Check cargo is available
+        if which::which("cargo").is_err() {
+            eprintln!(
+                "{} {} not found. Install Rust: https://rustup.rs",
+                red.apply_to("✗"),
+                bold.apply_to("cargo")
+            );
+            std::process::exit(1);
+        }
+
+        // Build WASM plugins
+        eprintln!(
+            "{}",
+            dim.apply_to("Building WASM plugins (wasm32-wasip1)...")
+        );
+        let status = Command::new("cargo")
+            .args([
+                "build",
+                "--release",
+                "--target",
+                "wasm32-wasip1",
+                "-p",
+                "llm_gateway",
+                "-p",
+                "prompt_gateway",
+            ])
+            .current_dir(&crates_dir)
+            .status()?;
+
+        if !status.success() {
+            bail!("WASM build failed");
+        }
+
+        // Build brightstaff
+        eprintln!("{}", dim.apply_to("Building brightstaff (native)..."));
+        let status = Command::new("cargo")
+            .args(["build", "--release", "-p", "brightstaff"])
+            .current_dir(&crates_dir)
+            .status()?;
+
+        if !status.success() {
+            bail!("brightstaff build failed");
+        }
+
+        let wasm_dir = crates_dir.join("target/wasm32-wasip1/release");
+        let native_dir = crates_dir.join("target/release");
+
+        println!("\n{}:", bold.apply_to("Build artifacts"));
+        println!("  {}", wasm_dir.join("prompt_gateway.wasm").display());
+        println!("  {}", wasm_dir.join("llm_gateway.wasm").display());
+        println!("  {}", native_dir.join("brightstaff").display());
+    } else {
+        let repo_root =
+            find_repo_root().ok_or_else(|| anyhow::anyhow!("Could not find repository root."))?;
+
+        let dockerfile = repo_root.join("Dockerfile");
+        if !dockerfile.exists() {
+            bail!("Dockerfile not found at {}", dockerfile.display());
+        }
+
+        println!("Building plano image from {}...", repo_root.display());
+        let status = Command::new("docker")
+            .args([
+                "build",
+                "-f",
+                &dockerfile.to_string_lossy(),
+                "-t",
+                &plano_docker_image(),
+                &repo_root.to_string_lossy(),
+                "--add-host=host.docker.internal:host-gateway",
+            ])
+            .status()?;
+
+        if !status.success() {
+            bail!("Docker build failed");
+        }
+
+        println!("plano image built successfully.");
+    }
+
+    Ok(())
+}