feat: resolve relative VIDEO_ARCHIVE_HOST via compose cwd (portable copy-path)

backend/config.py

@@ -26,16 +26,20 @@ VIDEO_ROOT = os.path.abspath(os.environ.get("VIDEO_ARCHIVE", os.path.join(DATA_D
 def archive_host_paths() -> dict:
     """Where the archive sits on the host — for the copy-path buttons (REQ-179).
 
-    ponytail: relative VIDEO_ARCHIVE_HOST (./data/archive) cannot be resolved
-    inside the container; set it absolute in .env or the buttons stay hidden."""
+    VIDEO_ARCHIVE_HOST may stay relative (portable across machines): compose
+    injects the host cwd as ARCHIVE_HOST_PWD (compose always has PWD — a
+    Windows-side run yields a drive-letter path, handled below), bare-metal
+    resolves against the process cwd (start.sh cds to the repo root)."""
     import re
     host = os.environ.get("VIDEO_ARCHIVE_HOST", "")
-    if os.path.isabs(host):
-        linux = host.rstrip("/")
-    elif VIDEO_ROOT != "/videos":   # bare-metal: VIDEO_ROOT is already the host path
-        linux = VIDEO_ROOT
-    else:
+    if host and not os.path.isabs(host):
+        base = os.environ.get("ARCHIVE_HOST_PWD") or os.getcwd()
+        host = os.path.abspath(os.path.join(base, host))
+    if not host and VIDEO_ROOT != "/videos":
+        host = VIDEO_ROOT   # bare-metal with no VIDEO_ARCHIVE_HOST at all
+    if not host:
         return {"linux": None, "windows": None}
+    linux = host.rstrip("/")
     if re.match(r"^[A-Za-z]:[\\/]", linux):
         return {"linux": None, "windows": linux.replace("/", "\\")}
     distro = os.environ.get("WSL_DISTRO_NAME", "")