[WIP] Refactor to decompose http_api into route modules and helpers

addons/thread-observability/app/src/thread_observability/api/app_meta.py

@@ -0,0 +1,55 @@
+"""Shared application metadata helpers for the HTTP API surface.
+
+Keeping these small, dependency-free utilities in a dedicated module reduces
+cross-cutting concerns in the main FastAPI app factory.
+"""
+
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+from ..utils.datetime import utc_now_iso
+
+
+def _read_addon_version() -> str:
+    """Read version from config.yaml so it never drifts from the manifest."""
+    here = Path(__file__).resolve()
+    candidates = [
+        Path("/opt/thread-observability/config.yaml"),  # baked into image
+        Path("/config.yaml"),  # mounted into container
+        Path("/app/config.yaml"),  # alt container layout
+        *(p / "config.yaml" for p in here.parents),  # walk up (covers dev tree)
+    ]
+    for candidate in candidates:
+        try:
+            if candidate.exists():
+                match = re.search(
+                    r"^version:\\s*([^\\s#]+)", candidate.read_text(), re.MULTILINE
+                )
+                if match:
+                    return match.group(1).strip().strip('"').strip("'")
+        except OSError:
+            continue
+    return "unknown"
+
+
+ADDON_VERSION = _read_addon_version()
+LOG_PATH = Path("/data/thread-observability/addon.log")
+
+# Ingress dashboard HTML. Loaded once because it's a static asset packaged
+# with the app.
+DASHBOARD_HTML = (Path(__file__).parent / "dashboard.html").read_text(encoding="utf-8")
+
+
+def utc_now() -> str:
+    return utc_now_iso()
+
+
+def tail_log(n: int = 80) -> list[str]:
+    if not LOG_PATH.exists():
+        return []
+    try:
+        return LOG_PATH.read_text(errors="replace").splitlines()[-n:]
+    except OSError:
+        return []