feat: standards, shared CI and release tooling for NAPALM drivers

STANDARDS.md binds every repository in the NAPALM org: one default branch,
Conventional Commits, the device-types contract, test-driven development,
clean-code limits, a quality ratchet for existing code, packaging rules and
releases by tag to PyPI.

napalm-standard holds what a tool can check: the conformance check (with
release rules on a tag), the quality ratchet (ported from netOrk's
quality_ratchet.py), and the Gitea release from the CHANGELOG section.
.gitea/workflows/driver.yml is the CI every driver calls; template/ is a new
driver's starting point and passes the check as it is.

napalm_standard/changelog.py

@@ -0,0 +1,25 @@
+"""The CHANGELOG.md section of one version, the text of its release."""
+
+from __future__ import annotations
+
+import re
+
+#: A version heading in CHANGELOG.md: "## [1.2.3] - 2026-10-01".
+_HEADING = re.compile(r"^## \[(?P<version>[^\]]+)\]", re.MULTILINE)
+
+
+def changelog_section(text: str, version: str) -> str | None:
+    """The body under ``## [version]`` up to the next version heading, or None."""
+    version = version.removeprefix("v")
+    headings = list(_HEADING.finditer(text))
+    for i, heading in enumerate(headings):
+        if heading.group("version") != version:
+            continue
+        line_end = text.find("\n", heading.end())
+        start = len(text) if line_end == -1 else line_end + 1
+        end = headings[i + 1].start() if i + 1 < len(headings) else len(text)
+        body = text[start:end].strip()
+        # Sections are sometimes closed by a horizontal rule; it is layout, not content.
+        body = re.sub(r"\n*^---\s*\Z", "", body, flags=re.MULTILINE).strip()
+        return body or None
+    return None