GRM-20: refactor(scripts): centralize constants, API clients, and HTTP status codes

- Add shared config.py with API URLs, regexes, timeouts, pagination
- Add GiteaClient and VikunjaClient in api_clients.py with pooled sessions
- Add APIError exception for unified HTTP error handling
- Refactor all scripts to use shared modules and http.HTTPStatus
- Rewrite unit tests to mock clients and use HTTPStatus constants
- Add tests for api_clients and config modules
- Achieve 100% test coverage

scripts/validate_commit_msg.py

@@ -12,12 +12,10 @@ import subprocess
 
 import click
 
+from gitea_runner_manager.config import CONVENTIONAL_RE
 from gitea_runner_manager.i18n import _
 
-CONVENTIONAL_RE = re.compile(
-    r"^(feat|fix|chore|docs|style|refactor|perf|test|ci|build|revert|BREAKING CHANGE)(\(.+\))?: .+"
-)
-TASK_ID_RE = re.compile(r"^GRM-\d+:")
+MASTER_TASK_ID_RE = re.compile(r"^GRM-\d+:")
 
 
 def first_line(text: str) -> str:
@@ -47,7 +45,7 @@ def main(commit_msg_file: str) -> None:
     subject = first_line(msg)
 
     if branch == "master":
-        if not TASK_ID_RE.match(subject):
+        if not MASTER_TASK_ID_RE.match(subject):
             raise click.ClickException(
                 _(
                     "Oops! Master branch commits must start with a task ID.\n"
@@ -56,7 +54,7 @@ def main(commit_msg_file: str) -> None:
                     subject=subject,
                 )
             )
-        remainder = TASK_ID_RE.sub("", subject).strip()
+        remainder = MASTER_TASK_ID_RE.sub("", subject).strip()
         if not CONVENTIONAL_RE.match(remainder):
             raise click.ClickException(
                 _(
@@ -68,7 +66,7 @@ def main(commit_msg_file: str) -> None:
             )
         return
 
-    if TASK_ID_RE.match(subject):
+    if MASTER_TASK_ID_RE.match(subject):
         raise click.ClickException(
             _(
                 "Oops! Do not include task ID (GRM-N) in feature branch commits.\n"