fix: use portable shebang in shell scripts

Change #!/bin/bash to #!/usr/bin/env bash for better portability
on systems like NixOS where /bin/bash doesn't exist.

Fixes #910

packages/coding-agent/examples/extensions/doom-overlay/doom/build.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Build DOOM for pi-doom using doomgeneric and Emscripten
 
 set -e

packages/coding-agent/scripts/migrate-sessions.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Migrate sessions from ~/.pi/agent/*.jsonl to proper session directories.
 # This fixes sessions created by the bug in v0.30.0 where sessions were

packages/mom/dev.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 
 CONTAINER_NAME="mom-sandbox"

packages/mom/docker.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Mom Docker Sandbox Management Script
 # Usage:

test.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 
 AUTH_FILE="$HOME/.pi/agent/auth.json"