dep-fetcher 0.1.2: multi-path resolution + accept untagged dev-state when manifest matches pin

- resolve_libs_dirs / resolve_modules_dirs return arrays of candidate
  paths (priority: opts override > opts.install_root-derived >
  engine.libs_dirs() / modules_dirs() > SPOREL_*_DIR env >
  install_root-derived fallback). first_existing walks the array to
  find the candidate that actually contains the requested manifest,
  so dev-tree layouts with libs and modules in different roots work
  without forcing the caller to pre-flatten.
- New case G: when describe fails because the repo has no tags at
  all (common during dev between tagged releases), accept the lib
  if its manifest.version matches the pin. Previously errored as
  "describe-fail" which made the pre-launch dep-check unusable in
  dev-tree runs.
- Dep pin: lib-core.git 0.1.0 -> 0.2.0 (token-auth + set_token).

manifest.lib

@@ -1,8 +1,8 @@
 {
     "id": "lib-management.dep-fetcher",
-    "version": "0.1.1",
+    "version": "0.1.2",
     "api_min": "0.1",
     "deps": [
-        {"id": "lib-core.git", "version": "0.1.0"}
+        {"id": "lib-core.git", "version": "0.2.0"}
     ]
 }