[Security] Argument injection in kiro/run.sh — missing `--` end-of-options separator

### Description

In `01-features/02-host-your-agent/01-runtime/04-coding-agents/03-code-agents-competition-e2e/coding_agents/kiro/run.sh`, the prompt is passed directly to `kiro-cli` without a `--` end-of-options separator:

```bash
case "$ACTION" in
interactive) exec kiro-cli ;;
chat) exec kiro-cli chat --no-interactive --trust-all-tools "$PROMPT" ;;
*) exec kiro-cli "$ACTION" "$PROMPT" ;;
esac
```

Since the prompt originates from an HTTP request body (via `healthcheck.py` or `connect.py`), an attacker can inject arbitrary `kiro-cli` flags by sending a prompt that starts with `--`. For example:

```bash
# POST /invocations with {"prompt": "--version"}
# Results in:
kiro-cli chat --no-interactive --trust-all-tools --version
# ^^^^^^^^^ interpreted as a flag, not text
```

This is argv flag smuggling: untrusted input is parsed as options because the data plane (prompt) and control plane (flags) share the same argv list without a boundary.

### Steps to Reproduce

```bash
# Mock kiro-cli to show how args are parsed:
cat > /tmp/kiro-cli << 'EOF'
#!/usr/bin/env bash
echo "kiro-cli called with:"; i=0; for a in "$@"; do echo " [$i] $a"; ((i++)); done
EOF
chmod +x /tmp/kiro-cli
export PATH="/tmp:$PATH"

# Simulate the launcher:
PROMPT="--version"
kiro-cli chat --no-interactive --trust-all-tools "$PROMPT"
# Output: [3] --version ← parsed as option, not positional text
```

### Suggested Fix

Add `--` before `"$PROMPT"`:

```bash
case "$ACTION" in
interactive) exec kiro-cli ;;
chat) exec kiro-cli chat --no-interactive --trust-all-tools -- "$PROMPT" ;;
*) exec kiro-cli "$ACTION" -- "$PROMPT" ;;
esac
```

The `--` signals end-of-options per POSIX convention. Everything after it is treated as positional text regardless of leading dashes.

### Severity

Medium — reachable by anyone who can POST to `/invocations` with an arbitrary prompt. The agent already runs with `--trust-all-tools`, so injecting additional flags could alter execution behavior.

Open 01-features/02-host-your-agent/01-runtime/04-coding-agents/03-code-agents-competition-e2e/coding_agents/kiro/run.sh and inspect the three kiro-cli invocations. Use the supplied mock kiro-cli reproduction with a --version prompt to verify that the prompt remains positional after the argument boundary is added.

Written by the indexing model from the issue text.