I will implement the Deno runtime compatibility plan as described in `WASI_DENO.md`.

**Plan:**

1. **Database Migration**:

   * Create a new migration `20260312000003_add_function_runtime.sql`.

   * Add `runtime` column to `functions.functions` table (TEXT, DEFAULT 'wasm').

   * Update existing functions to have `runtime = 'wasm'`.

2. **Update Dependencies**:

   * Add `deno_core` to `functions/Cargo.toml`.

   * *Note*: I will start with `deno_core` to avoid potential build OOM issues with the full `deno_runtime`. I will implement a minimal JS runtime capable of executing scripts and returning results.

3. **Update Data Models**:

   * Modify `Function` struct in `functions/src/models.rs` to include the `runtime` field.

   * Update `DeployRequest` struct in `functions/src/models.rs` to accept an optional `runtime` field.

4. **Implement Deno Runtime**:

   * Create `functions/src/deno_runtime.rs`.

   * Implement `DenoRuntime` struct using `deno_core::JsRuntime`.

   * Implement `execute` method that initializes the runtime, executes the provided code, and captures output.

5. **Update Handlers**:

   * Modify `deploy_function` in `functions/src/handlers.rs` to handle the `runtime` field.

   * Modify `invoke_function` in `functions/src/handlers.rs` to switch between `WasmRuntime` and `DenoRuntime` based on the function's `runtime` column.

6. **Integration Testing**:

   * Update `tests/integration/functions.test.ts` to include a test case for deploying and invoking a JavaScript/TypeScript function.

7. **Verification**:

   * Run `cargo build` to ensure dependencies compile.

   * Run `npm test functions.test.ts` to verify functionality.