fix: invoke .sh hooks via bash prefix; add version for cache invalidation

Fixes #993 (Permission denied on hook scripts) without relying on
client-side +x preservation.

The hook executor spawns commands via /bin/sh -c, which requires +x
to execute a script directly. Prefixing with bash reads the script
as data — mode bits are irrelevant. This works on all Claude Code
versions, whereas the client-side chmod fix (claude-cli #24666) only
shipped in v2.1.86.

All 3 scripts declare #!/bin/bash and use bashisms ([[ ]], =~), so
bash (not sh) is the correct interpreter.

The version field forces a fresh cache path (1.0.0/ instead of
unknown/), ensuring the new hooks.json reaches users with stale
caches.

plugins/ralph-loop/hooks/hooks.json

@@ -6,7 +6,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${CLAUDE_PLUGIN_ROOT}/hooks/stop-hook.sh"
+            "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/stop-hook.sh\""
           }
         ]
       }