fix zero-gravity doubled-v bug in Dockerfile asset names

Remove leading 'v' from ZERO_GRAVITY_VERSION values in context.yml
(1.0.6, 3.0.8 instead of v1.0.6, v3.0.8) and add defensive stripping in
zerog.Dockerfile (VERSION=${ZERO_GRAVITY_VERSION#v}) to prevent
asset names like aristotle-vv1.0.6.tar.gz / galileo-vv3.0.8.tar.gz.

The asset filename is always <spec>-v<version>.tar.gz, and the Dockerfile
was adding a 'v' prefix to versions that already had one.

Verified URLs resolve:
- aristotle: https://github.com/0gfoundation/0gchain-Aristotle/releases/download/v1.0.6/aristotle-v1.0.6.tar.gz
- galileo: https://github.com/0gfoundation/0gchain-NG/releases/download/v3.0.8/galileo-v3.0.8.tar.gz

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

zero-gravity/geth/zero-gravity-aristotle-geth-pruned-pebble-path.yml

@@ -35,7 +35,7 @@ services:
       context: ./zero-gravity
       dockerfile: zerog.Dockerfile
       args:
-        ZERO_GRAVITY_VERSION: ${ZERO_GRAVITY_ARISTOTLE_ZEROG_VERSION:-v1.0.6}
+        ZERO_GRAVITY_VERSION: ${ZERO_GRAVITY_ARISTOTLE_ZEROG_VERSION:-1.0.6}
         ZERO_GRAVITY_CHAIN_SPEC: aristotle
     sysctls:
       # TCP Performance
@@ -118,7 +118,7 @@ services:
       context: ./zero-gravity
       dockerfile: zerog.Dockerfile
       args:
-        ZERO_GRAVITY_VERSION: ${ZERO_GRAVITY_ARISTOTLE_ZEROG_VERSION:-v1.0.6}
+        ZERO_GRAVITY_VERSION: ${ZERO_GRAVITY_ARISTOTLE_ZEROG_VERSION:-1.0.6}
         ZERO_GRAVITY_CHAIN_SPEC: aristotle
     ports:
       - 19914:19914

zero-gravity/geth/zero-gravity-galileo-geth-pruned-pebble-path.yml

@@ -35,7 +35,7 @@ services:
       context: ./zero-gravity
       dockerfile: zerog.Dockerfile
       args:
-        ZERO_GRAVITY_VERSION: ${ZERO_GRAVITY_GALILEO_ZEROG_VERSION:-v3.0.8}
+        ZERO_GRAVITY_VERSION: ${ZERO_GRAVITY_GALILEO_ZEROG_VERSION:-3.0.8}
         ZERO_GRAVITY_CHAIN_SPEC: galileo
     sysctls:
       # TCP Performance
@@ -118,7 +118,7 @@ services:
       context: ./zero-gravity
       dockerfile: zerog.Dockerfile
       args:
-        ZERO_GRAVITY_VERSION: ${ZERO_GRAVITY_GALILEO_ZEROG_VERSION:-v3.0.8}
+        ZERO_GRAVITY_VERSION: ${ZERO_GRAVITY_GALILEO_ZEROG_VERSION:-3.0.8}
         ZERO_GRAVITY_CHAIN_SPEC: galileo
     ports:
       - 16172:16172

zero-gravity/zerog.Dockerfile

@@ -22,20 +22,23 @@ ARG ZERO_GRAVITY_CHAIN_SPEC
 # curl uses -f (fail on HTTP error). Without it a 404 HTML body is written into the .tar.gz
 # and the build dies several layers later at "tar: not in gzip format" -- an error that
 # points nowhere near the real cause. That has cost three separate misdiagnoses.
+#
+# Strip leading 'v' from version if present, to avoid doubled-v (e.g., vv1.0.6 -> v1.0.6)
 RUN set -eu; \
-    ASSET="${ZERO_GRAVITY_CHAIN_SPEC}-v${ZERO_GRAVITY_VERSION}.tar.gz"; \
+    VERSION="${ZERO_GRAVITY_VERSION#v}"; \
+    ASSET="${ZERO_GRAVITY_CHAIN_SPEC}-v${VERSION}.tar.gz"; \
     if [ "${ZERO_GRAVITY_CHAIN_SPEC}" = "aristotle" ]; then \
         REPO="0gfoundation/0gchain-Aristotle"; \
-        TAGS="${ZERO_GRAVITY_VERSION} v${ZERO_GRAVITY_VERSION} ${ZERO_GRAVITY_CHAIN_SPEC}-v${ZERO_GRAVITY_VERSION}"; \
+        TAGS="${VERSION} v${VERSION} ${ZERO_GRAVITY_CHAIN_SPEC}-v${VERSION}"; \
     else \
         REPO="0gfoundation/0gchain-NG"; \
-        TAGS="v${ZERO_GRAVITY_VERSION} ${ZERO_GRAVITY_CHAIN_SPEC}-v${ZERO_GRAVITY_VERSION} ${ZERO_GRAVITY_VERSION}"; \
+        TAGS="v${VERSION} ${ZERO_GRAVITY_CHAIN_SPEC}-v${VERSION} ${VERSION}"; \
     fi; \
     for TAG in ${TAGS}; do \
         URL="https://github.com/${REPO}/releases/download/${TAG}/${ASSET}"; \
         echo "0g: trying tag '${TAG}' -> ${URL}"; \
         if curl -fsSL "${URL}" -o "/tmp/${ASSET}"; then \
-            echo "0g: resolved ${ZERO_GRAVITY_CHAIN_SPEC} ${ZERO_GRAVITY_VERSION} from tag '${TAG}'"; \
+            echo "0g: resolved ${ZERO_GRAVITY_CHAIN_SPEC} ${VERSION} from tag '${TAG}'"; \
             break; \
         fi; \
         rm -f "/tmp/${ASSET}"; \
@@ -44,7 +47,7 @@ RUN set -eu; \
         echo "0g: FATAL - no release asset '${ASSET}' found in ${REPO} under any of: ${TAGS}" >&2; \
         echo "0g: aristotle and galileo are SEPARATE repos on SEPARATE version lines" >&2; \
         echo "0g: aristotle = 0gchain-Aristotle (1.0.x), galileo = 0gchain-NG (3.0.x)" >&2; \
-        echo "0g: check that version '${ZERO_GRAVITY_VERSION}' exists for '${ZERO_GRAVITY_CHAIN_SPEC}'" >&2; \
+        echo "0g: check that version '${VERSION}' exists for '${ZERO_GRAVITY_CHAIN_SPEC}'" >&2; \
         exit 1; \
     fi
 
@@ -67,7 +70,7 @@ RUN set -eu; \
 # version, nor the layout. Assert on the binaries here so the NEXT upstream reshuffle
 # reports itself at the point of failure instead.
 RUN set -eu; \
-    SRC="/tmp/${ZERO_GRAVITY_CHAIN_SPEC}-v${ZERO_GRAVITY_VERSION}"; \
+    SRC="/tmp/${ZERO_GRAVITY_CHAIN_SPEC}-v${VERSION}"; \
     tar -xzf "${SRC}.tar.gz" -C /tmp; \
     mkdir -p /0g; \
     if [ -d "${SRC}/rpc" ]; then \
@@ -88,7 +91,7 @@ RUN set -eu; \
     done; \
     if [ -n "${missing}" ]; then \
         echo "0g: FATAL - missing after extraction:${missing}" >&2; \
-        echo "0g: ${ZERO_GRAVITY_CHAIN_SPEC} v${ZERO_GRAVITY_VERSION} tarball layout not recognised." >&2; \
+        echo "0g: ${ZERO_GRAVITY_CHAIN_SPEC} v${VERSION} tarball layout not recognised." >&2; \
         echo "0g: known layouts are '<root>/rpc/bin/' (per-profile) and '<root>/bin/' (flat)." >&2; \
         echo "0g: contents of /0g were:" >&2; \
         ls -la /0g >&2 || true; \