Merge PR #49: Use portable shebang across all shell scripts

Replace #!/bin/bash with #!/usr/bin/env bash for better portability
across different Unix systems (e.g. NixOS) where bash may be installed
in non-standard locations. Also fix remaining shebangs in files added
after the original PR was created.

Includes prepare_runtime_bin() helper for test PATH isolation.

Author: SihaoLiu

hooks/lib/loop-common.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Common functions for RLCR loop hooks
 #

hooks/lib/template-loader.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Template loading functions for RLCR loop hooks
 #

hooks/loop-bash-validator.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # PreToolUse Hook: Validate Bash commands for RLCR loop and PR loop
 #

hooks/loop-codex-stop-hook.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Stop Hook for RLCR loop
 #

hooks/loop-edit-validator.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # PreToolUse Hook: Validate Edit paths for RLCR loop and PR loop
 #

hooks/loop-plan-file-validator.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # UserPromptSubmit hook for plan file validation during RLCR loop
 #

hooks/loop-post-bash-hook.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # PostToolUse Bash Hook for RLCR loop
 #

hooks/loop-read-validator.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # PreToolUse Hook: Validate Read access for RLCR loop and PR loop files
 #

hooks/loop-write-validator.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # PreToolUse Hook: Validate Write paths for RLCR loop and PR loop
 #

hooks/pr-loop-stop-hook.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Stop Hook for PR loop
 #