Enhance logging and timing in CLI and session operations

- Updated the `_print_checks` function to replace console prints with logging functions for better traceability.
- Introduced timing functionality in the `doctor`, `dry_run`, and `up` functions to log the duration of preflight checks.
- Modified the `wait_ssh` function to accept a logging callback, improving SSH wait feedback.
- Enhanced the `mark` method in `PhaseTimes` to log phase durations, aiding in performance analysis.
- Updated various remote scripts to ensure error messages are printed to stderr for better error handling.

src/gpu_rent/remote/install_llamacpp.sh

@@ -14,7 +14,7 @@ UNIT="gpu-rent-llamacpp"
 REPO="https://github.com/ggml-org/llama.cpp.git"
 API_BASE="https://api.github.com/repos/ggml-org/llama.cpp"
 
-log() { echo "[gpu-rent-llamacpp] $*"; }
+log() { echo "[gpu-rent-llamacpp] $*" >&2; }
 
 if [[ "$(id -u)" -ne 0 ]]; then
   echo "нужен root" >&2
@@ -66,11 +66,11 @@ print(cands[0][1] if cands else "")
 }
 
 resolve_release_tag() {
+  # stdout = tag only (no log lines — callers capture via $())
   if [[ -n "$LLAMACPP_TAG" ]]; then
     echo "$LLAMACPP_TAG"
     return
   fi
-  log "WARN: LLAMACPP_TAG/ASSET_URL не заданы — берём latest (нет pin). См. docs/llm.md"
   curl -fsSL "${API_BASE}/releases/latest" | python3 -c \
     'import json,sys; print(json.load(sys.stdin).get("tag_name") or "")'
 }
@@ -228,9 +228,13 @@ else
     echo "asset-url" >"$STAMP"
     chown "${SWARM_USER}:${SWARM_USER}" "$STAMP"
   else
+    if [[ -z "$LLAMACPP_TAG" ]]; then
+      log "WARN: LLAMACPP_TAG/ASSET_URL не заданы — берём latest (нет pin). См. docs/llm.md"
+    fi
     tag="$(resolve_release_tag)"
-    if [[ -z "$tag" ]]; then
-      log "не удалось определить release tag"
+    tag="$(printf '%s' "$tag" | tr -d '\r' | head -n1 | awk 'NF{print; exit}')"
+    if [[ -z "$tag" || "$tag" == *" "* || "$tag" == *"["* ]]; then
+      log "не удалось определить release tag (got: ${tag:-empty})"
       exit 1
     fi
     if ! build_cuda_from_source "$tag"; then