feat: add display UI with splash screen, dashboard, and RSSI sparkline

Implement full SSD1306 OLED display support:
- Splash screen on boot (1.5s) with project name, version, board
- Dashboard showing radio state, config, counters, RSSI/SNR
- RSSI history sparkline (64-sample ring buffer, 2px-wide bars)
- DisplayOn/DisplayOff host commands routed via dedicated channel
- Pure render functions against generic DrawTarget (no hardware coupling)
- Display on/off control bypasses radio task entirely

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

vendor/zerocopy/ci/check_actions.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+#
+# Copyright 2025 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -eo pipefail
+
+script_name="ci/check_actions.sh"
+
+# Ensure action-validator is installed
+if [ ! -x "$HOME/.cargo/bin/action-validator" ]; then
+    echo "$script_name: action-validator not found, installing..." >&2
+    # Install specific version to ensure reproducibility
+    cargo install -q action-validator --version 0.8.0 --locked
+fi
+export PATH="$HOME/.cargo/bin:$PATH"
+
+# Files to exclude from validation (e.g., because they are not Actions/Workflows)
+# Use relative paths matching `find .github` output
+EXCLUDE_FILES=(
+    "./.github/dependabot.yml"
+    "./.github/release.yml"
+)
+
+failed=0
+
+# Use process substitution and while loop to handle filenames with spaces robustly
+while IFS= read -r -d '' file; do
+    # Check if file is in exclusion list
+    for exclude in "${EXCLUDE_FILES[@]}"; do
+        if [[ "$file" == "$exclude" ]]; then
+            continue 2
+        fi
+    done
+
+    if ! output=$(action-validator "$file" 2>&1); then
+        echo "$script_name: ❌ Validation failed for $file" >&2
+        echo "$output" | sed "s|^|$script_name:   |" >&2
+        failed=1
+    fi
+done < <(find ./.github -type f \( -iname '*.yml' -o -iname '*.yaml' \) -print0)
+
+if [[ $failed -ne 0 ]]; then
+    echo "$script_name: One or more files failed validation." >&2
+    exit 1
+fi

vendor/zerocopy/ci/check_all_toolchains_tested.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+#
+# Copyright 2024 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -eo pipefail
+
+# Check whether the set of toolchains tested in this file (other than
+# 'msrv', 'stable', and 'nightly') is equal to the set of toolchains
+# listed in the 'package.metadata.build-rs' section of Cargo.toml.
+#
+# If the inputs to `diff` are not identical, `diff` exits with a
+# non-zero error code, which causes this script to fail (thanks to
+# `set -e`).
+diff \
+  <(yq -r '.jobs.build_test.strategy.matrix.toolchain | .[]' .github/workflows/ci.yml | \
+    sort -u | grep -v '^\(msrv\|stable\|nightly\)$') \
+  <(cargo metadata -q --format-version 1 | \
+    jq -r ".packages[] | select(.name == \"zerocopy\").metadata.\"build-rs\" | keys | .[]" | \
+    sort -u) >&2

vendor/zerocopy/ci/check_fmt.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+#
+# Copyright 2024 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -eo pipefail
+
+if [[ "$1" == "--fix" ]]; then
+    FMT_FLAGS=""
+else
+    FMT_FLAGS="--check"
+fi
+
+find . -iname '*.rs' -type f -not -path './target/*' -not -iname '*.expected.rs' -not -path './vendor/*' -not -path './tools/vendor/*' -print0 | xargs -0 --no-run-if-empty ./cargo.sh +nightly fmt $FMT_FLAGS -- >&2

vendor/zerocopy/ci/check_job_dependencies.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+#
+# Copyright 2024 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -eo pipefail
+which yq > /dev/null
+jobs=$(for i in $(find .github -iname '*.yaml' -or -iname '*.yml')
+  do
+    # Select jobs that are triggered by pull request.
+    if yq -e '.on | has("pull_request")' "$i" 2>/dev/null >/dev/null
+    then
+      # This gets the list of jobs that all-jobs-succeed does not depend on.
+      comm -23 \
+        <(yq -r '.jobs | keys | .[]' "$i" | sort | uniq) \
+        <(yq -r '.jobs["all-jobs-succeed"].needs[]' "$i" | sort | uniq)
+    fi
+
+  # The grep call here excludes all-jobs-succeed from the list of jobs that
+  # all-jobs-succeed does not depend on.  If all-jobs-succeed does
+  # not depend on itself, we do not care about it.
+  done | sort | uniq | (grep -v '^all-jobs-succeed$' || true)
+)
+
+if [ -n "$jobs" ]
+then
+  missing_jobs="$(echo "$jobs" | tr ' ' '\n')"
+  echo "all-jobs-succeed missing dependencies on some jobs: $missing_jobs" | tee -a $GITHUB_STEP_SUMMARY >&2
+  exit 1
+fi

vendor/zerocopy/ci/check_msrv_is_minimal.sh

@@ -0,0 +1,72 @@
+#!/usr/bin/env bash
+#
+# Copyright 2025 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -eo pipefail
+
+read -r -d '' PYTHON_SCRIPT <<'EOF' || true
+import sys
+import json
+
+def parse_version(v):
+    """Converts a version string to a tuple of integers."""
+    return tuple(map(int, v.split(".")))
+
+def main():
+    """
+    Checks that the package's MSRV is strictly lower than any version
+    specified in `package.metadata.build-rs`.
+    """
+    try:
+        data = json.load(sys.stdin)
+    except json.JSONDecodeError as e:
+        print(f"Error parsing JSON from cargo metadata: {e}", file=sys.stderr)
+        sys.exit(1)
+
+    # Find the zerocopy package
+    try:
+        pkg = next(p for p in data["packages"] if p["name"] == "zerocopy")
+    except StopIteration:
+        print("Error: zerocopy package not found in metadata", file=sys.stderr)
+        sys.exit(1)
+
+    msrv_str = pkg.get("rust_version")
+    if not msrv_str:
+        print("Error: rust-version not found in Cargo.toml", file=sys.stderr)
+        sys.exit(1)
+
+    try:
+        msrv = parse_version(msrv_str)
+    except ValueError:
+        print(f"Error: Invalid MSRV format: {msrv_str}", file=sys.stderr)
+        sys.exit(1)
+
+    build_rs_versions = (pkg.get("metadata") or {}).get("build-rs", {})
+
+    failed = False
+    for name, ver_str in build_rs_versions.items():
+        try:
+            ver = parse_version(ver_str)
+        except ValueError:
+            print(f"Warning: Skipping invalid version format for {name}: {ver_str}", file=sys.stderr)
+            continue
+
+        # Check that MSRV < Version (strictly lower)
+        if not (msrv < ver):
+            print(f"Error: MSRV ({msrv_str}) is not strictly lower than {name} ({ver_str})", file=sys.stderr)
+            failed = True
+
+    if failed:
+        sys.exit(1)
+
+if __name__ == "__main__":
+    main()
+EOF
+
+cargo metadata --format-version 1 --no-deps | python3 -c "$PYTHON_SCRIPT"

vendor/zerocopy/ci/check_readme.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+#
+# Copyright 2024 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -eo pipefail
+
+# Install again in case the installation failed during the
+# `generate_cache` step. We treat that step as best-effort and
+# suppress all errors from it.
+cargo install -q cargo-readme --version 3.2.0
+
+diff <(cargo -q run --config tools/.cargo/config.toml --manifest-path tools/Cargo.toml -p generate-readme) README.md >&2
+exit $?

vendor/zerocopy/ci/check_stale_stderr.sh

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+#
+# Copyright 2026 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -eo pipefail
+
+# Directories to search
+DIRS=("tests" "zerocopy-derive/tests")
+
+EXIT_CODE=0
+
+for dir in "${DIRS[@]}"; do
+    if [ ! -d "$dir" ]; then
+        echo "Warning: Directory $dir does not exist, skipping." >&2
+        continue
+    fi
+
+    # Find all .stderr files
+    while IFS= read -r -d '' stderr_file; do
+        # Strip .stderr extension
+        base="${stderr_file%.stderr}"
+
+        # Strip toolchain suffixes
+        base="${base%.msrv}"
+        base="${base%.stable}"
+        base="${base%.nightly}"
+
+        # Construct the corresponding .rs file path
+        rs_file="${stderr_file%.stderr}.rs"
+        rs_file="${base}.rs"
+
+        # Check if the .rs file exists. The `-e` flag checks if file exists:
+        # It returns true for regular files and valid symlinks, and false for
+        # broken symlinks or missing files.
+        if [ ! -e "$rs_file" ]; then
+            echo "Error: Orphaned stderr file found: $stderr_file" >&2
+            echo "       Missing regular file or valid symlink: $rs_file" >&2
+            EXIT_CODE=1
+        fi
+    done < <(find "$dir" -name "*.stderr" -print0)
+done
+
+if [ "$EXIT_CODE" -eq 1 ]; then
+    echo "Found stale .stderr files. Please delete them." >&2
+fi
+
+exit "$EXIT_CODE"

vendor/zerocopy/ci/check_todo.sh

@@ -0,0 +1,82 @@
+#!/usr/bin/env bash
+#
+# Copyright 2025 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -euo pipefail
+
+# This allows us to leave XODO comments in this file and have them still be
+# picked up by this script without having the script itself trigger false
+# positives. The alternative would be to exclude this script entirely, which
+# would mean that we couldn't use XODO comments in this script.
+KEYWORD=$(echo XODO | sed -e 's/X/T/')
+
+# Make sure `rg` is installed (if this fails, `set -e` above will cause the
+# script to exit).
+rg --version >/dev/null
+
+# -H: Print filename (default for multiple files/recursive)
+# -n: Print line number
+# -w: Match whole words
+# Match TODO, TODO-check-disable, and TODO-check-enable
+PATTERN="$KEYWORD|$KEYWORD-check-disable|$KEYWORD-check-enable"
+output=$(rg -H -n -w "$PATTERN" "$@" || true)
+
+commit_output=$(git log -1 --pretty=%B 2>/dev/null | rg -n -w "$PATTERN" || true)
+if [ -n "$commit_output" ]; then
+  commit_output=$(echo "$commit_output" | sed "s/^/COMMIT_MESSAGE:/")
+  output="$commit_output${output:+$'\n'$output}"
+fi
+
+if [ -z "$output" ]; then
+  exit 0
+fi
+
+# Track the disabled state for each file. Since we process lines in order for
+# each file, we can maintain state. However, rg output might interleave files if
+# not sorted, but usually it's grouped. To be safe, we sort the output by
+# filename and line number.
+sorted_output=$(echo "$output" | sort -t: -k1,1 -k2,2n)
+
+exit_code=0
+current_file=""
+disabled=0
+
+while IFS= read -r line; do
+  if [[ "$line" =~ ^(.*):([0-9]+):(.*)$ ]]; then
+    file="${BASH_REMATCH[1]}"
+    content="${BASH_REMATCH[3]}"
+  else
+    echo "Error: could not parse rg output line: $line" >&2
+    exit 1
+  fi
+
+  if [ "$file" != "$current_file" ]; then
+    current_file="$file"
+    disabled=0
+  fi
+
+  if [[ "$content" == *"$KEYWORD-check-disable"* ]]; then
+    disabled=1
+  elif [[ "$content" == *"$KEYWORD-check-enable"* ]]; then
+    disabled=0
+  elif [[ "$content" == *"$KEYWORD"* ]]; then
+    if [ "$disabled" -eq 0 ]; then
+      if [ "$exit_code" -eq 0 ]; then
+        echo "Found $KEYWORD markers in the codebase." >&2
+        echo "$KEYWORD is used for tasks that should be done before merging a PR; if you want to leave a message in the codebase, use FIXME." >&2
+        echo "If you need to allow a $KEYWORD, wrap it in $KEYWORD-check-disable and $KEYWORD-check-enable." >&2
+        echo "" >&2
+        exit_code=1
+      fi
+      echo "$line" >&2
+    fi
+  fi
+done <<< "$sorted_output"
+
+exit $exit_code

vendor/zerocopy/ci/check_versions.sh

@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+#
+# Copyright 2024 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -eo pipefail
+
+# Usage: version <crate-name>
+function version {
+  cargo metadata -q --format-version 1 | jq -r ".packages[] | select(.name == \"$1\").version"
+}
+
+ver_zerocopy=$(version zerocopy)
+ver_zerocopy_derive=$(version zerocopy-derive)
+
+# Usage: dependency-version <kind> <target>
+function dependency-version {
+  KIND="$1"
+  TARGET="$2"
+  cargo metadata -q --format-version 1 \
+    | jq -r ".packages[] | select(.name == \"zerocopy\").dependencies[] | select((.name == \"zerocopy-derive\") and .kind == $KIND and .target == $TARGET).req"
+}
+
+# The non-dev dependency version (kind `null` filters out the dev
+# dependency, and target `null` filters out the targeted version).
+zerocopy_derive_dep_ver=$(dependency-version null null)
+
+# The non-dev dependency, targeted version (kind `null` filters out
+# the dev dependency).
+zerocopy_derive_targeted_ver=$(dependency-version null '"cfg(any())"')
+
+# The dev dependency version (kind `"dev"` selects only the dev
+# dependency).
+zerocopy_derive_dev_dep_ver=$(dependency-version '"dev"' null)
+
+function assert-match {
+  VER_A="$1"
+  VER_B="$2"
+  SUCCESS_MSG="$3"
+  FAILURE_MSG="$4"
+  if [[ "$VER_A" == "$VER_B" ]]; then
+    echo "$SUCCESS_MSG" | tee -a $GITHUB_STEP_SUMMARY
+  else
+    echo "$FAILURE_MSG" | tee -a $GITHUB_STEP_SUMMARY >&2
+    exit 1
+  fi
+}
+
+assert-match "$ver_zerocopy" "$ver_zerocopy_derive" \
+  "Same crate version ($ver_zerocopy) found for zerocopy and zerocopy-derive." \
+  "Different crate versions found for zerocopy ($ver_zerocopy) and zerocopy-derive ($ver_zerocopy_derive)."
+
+# Note the leading `=` sign - the dependency needs to be an exact one.
+assert-match "=$ver_zerocopy_derive" "$zerocopy_derive_dep_ver" \
+  "zerocopy depends upon same version of zerocopy-derive in-tree ($zerocopy_derive_dep_ver)." \
+  "zerocopy depends upon different version of zerocopy-derive ($zerocopy_derive_dep_ver) than the one in-tree ($ver_zerocopy_derive)."
+
+# Note the leading `=` sign - the dependency needs to be an exact one.
+assert-match "=$ver_zerocopy_derive" "$zerocopy_derive_dev_dep_ver" \
+  "In dev mode, zerocopy depends upon same version of zerocopy-derive in-tree ($zerocopy_derive_dev_dep_ver)." \
+  "In dev mode, zerocopy depends upon different version of zerocopy-derive ($zerocopy_derive_dev_dep_ver) than the one in-tree ($ver_zerocopy_derive)."
+
+assert-match "$zerocopy_derive_dep_ver" "$zerocopy_derive_targeted_ver" \
+  "Same crate version ($zerocopy_derive_dep_ver) found for optional and targeted zerocopy-derive dependency." \
+  "Different crate versions found for optional ($zerocopy_derive_dep_ver) and targeted ($zerocopy_derive_targeted_ver) dependency."

vendor/zerocopy/ci/release_crate_version.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+#
+# Copyright 2024 The Fuchsia Authors
+#
+# Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+# <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+# license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+set -e
+
+if [ $# -ne 1 ]; then
+    echo "Usage: $0 <version>" >&2
+    exit 1
+fi
+
+VERSION="$1"
+
+sed -i -e "s/^zerocopy-derive = { version = \"=[0-9a-zA-Z\.-]*\"/zerocopy-derive = { version = \"=$VERSION\"/" Cargo.toml
+sed -i -e "s/^version = \"[0-9a-zA-Z\.-]*\"/version = \"$VERSION\"/" Cargo.toml zerocopy-derive/Cargo.toml
+
+# Ensure that `Cargo.lock` is updated.
+cargo generate-lockfile

vendor/zerocopy/ci/validate_auto_approvers.py

@@ -0,0 +1,142 @@
+#!/usr/bin/env python3
+
+import argparse
+import json
+import re
+import sys
+import posixpath
+import os
+
+# Exit codes
+SUCCESS = 0
+NOT_APPROVED = 1
+TECHNICAL_ERROR = 255
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Validate PR changes against auto-approver rules."
+    )
+    parser.add_argument(
+        "--config",
+        default=".github/auto-approvers.json",
+        help="Path to the rules JSON.",
+    )
+    parser.add_argument(
+        "--changed-files", help="Path to the fetched changed files JSON."
+    )
+    parser.add_argument(
+        "--expected-count", type=int, help="Total number of files expected in the PR."
+    )
+    parser.add_argument(
+        "--contributors", nargs="+", help="List of GitHub usernames to validate."
+    )
+    parser.add_argument(
+        "--check-config",
+        action="store_true",
+        help="Only validate the configuration file and exit.",
+    )
+    args = parser.parse_args()
+
+    # REGEX: Strict path structure, prevents absolute paths and weird characters
+    VALID_PATH = re.compile(r"^([a-zA-Z0-9_.-]+/)+$")
+
+    # Load and validate config
+    try:
+        with open(args.config) as f:
+            rules = json.load(f)
+    except FileNotFoundError:
+        print(f"::error::❌ Config file not found at {args.config}")
+        sys.exit(TECHNICAL_ERROR)
+    except json.JSONDecodeError as e:
+        print(f"::error::❌ Failed to parse config JSON: {e}")
+        sys.exit(TECHNICAL_ERROR)
+
+    safe_rules = {}
+    for directory, users in rules.items():
+        if not isinstance(users, list):
+            print(
+                f"::error::❌ Users for '{directory}' must be a JSON array (list), not a string."
+            )
+            sys.exit(TECHNICAL_ERROR)
+
+        if not VALID_PATH.match(directory) or ".." in directory.split("/"):
+            print(f"::error::❌ Invalid config path: {directory}")
+            sys.exit(TECHNICAL_ERROR)
+
+        safe_rules[directory] = [str(u).lower() for u in users]
+
+    if not args.check_config:
+        # Validate that required arguments are present if not in --check-config mode
+        if not (
+            args.changed_files and args.expected_count is not None and args.contributors
+        ):
+            print(
+                "::error::❌ Missing required arguments: --changed-files, --expected-count, and --contributors are required unless --check-config is used."
+            )
+            sys.exit(TECHNICAL_ERROR)
+
+        # Load and flatten changed files
+        try:
+            with open(args.changed_files) as f:
+                file_objects = json.load(f)
+        except FileNotFoundError:
+            print(f"::error::❌ Changed files JSON not found at {args.changed_files}")
+            sys.exit(TECHNICAL_ERROR)
+        except json.JSONDecodeError as e:
+            print(f"::error::❌ Failed to parse changed files JSON: {e}")
+            sys.exit(TECHNICAL_ERROR)
+
+        if not file_objects or len(file_objects) != args.expected_count:
+            print(
+                f"::error::❌ File truncation mismatch or empty PR. Expected {args.expected_count}, got {len(file_objects) if file_objects else 0}."
+            )
+            sys.exit(TECHNICAL_ERROR)
+
+        if not all(isinstance(obj, list) for obj in file_objects):
+            print("::error::❌ Invalid payload format. Expected a list of lists.")
+            sys.exit(TECHNICAL_ERROR)
+
+        changed_files = [path for obj in file_objects for path in obj]
+
+        # Validate every file against every contributor
+        contributors = set(str(c).lower() for c in args.contributors)
+        print(f"👥 Validating contributors: {', '.join(contributors)}")
+
+        for raw_file_path in changed_files:
+            file_path = posixpath.normpath(raw_file_path)
+
+            # Find the most specific (longest) matching directory rule.
+            longest_match_dir = None
+            for directory in safe_rules.keys():
+                if file_path.startswith(directory):
+                    if longest_match_dir is None or len(directory) > len(
+                        longest_match_dir
+                    ):
+                        longest_match_dir = directory
+
+            # First, explicitly fail if the file isn't covered by ANY rule.
+            if not longest_match_dir:
+                print(
+                    f"::error::❌ File '{file_path}' does not fall under any configured auto-approve directory."
+                )
+                sys.exit(NOT_APPROVED)
+
+            # Then, verify every contributor has access to that specific rule.
+            for user in contributors:
+                if user not in safe_rules[longest_match_dir]:
+                    print(
+                        f"::error::❌ Contributor @{user} not authorized for '{file_path}'."
+                    )
+                    sys.exit(NOT_APPROVED)
+
+    if args.check_config:
+        print("✅ Configuration is structurally valid")
+    else:
+        print("✅ Validation passed")
+
+    sys.exit(SUCCESS)
+
+
+if __name__ == "__main__":
+    main()