fix(install): explicit docker.io usage (#2850)

# What does this PR do?

When podman is used and the registry is omitted, podman will prompt the
user. However, we're piping the output of podman to /dev/null and the
user will not see the prompt, the script will end abruptly and this is
confusing.

This commit explicitly uses the docker.io registry for the ollama image
and the llama-stack image so that the prompt is avoided.

<!-- If resolving an issue, uncomment and update the line below -->
<!-- Closes #[issue-number] -->

## Test Plan
<!-- Describe the tests you ran to verify your changes with result
summaries. *Provide clear instructions so the plan can be easily
re-executed.* -->

I ran the script on a machine with podman and the issue was resolved

## Image

Before the fix, this is what would happen:

<img width="748" height="95" alt="image"
src="https://github.com/user-attachments/assets/9c609f88-c0a8-45e7-a789-834f64f601e5"
/>

Signed-off-by: Omer Tuchfeld <omer@tuchfeld.dev>

scripts/install.sh

@@ -15,7 +15,7 @@ set -Eeuo pipefail
 PORT=8321
 OLLAMA_PORT=11434
 MODEL_ALIAS="llama3.2:3b"
-SERVER_IMAGE="llamastack/distribution-ollama:0.2.2"
+SERVER_IMAGE="docker.io/llamastack/distribution-ollama:0.2.2"
 WAIT_TIMEOUT=300
 
 log(){ printf "\e[1;32m%s\e[0m\n" "$*"; }
@@ -165,7 +165,7 @@ log "🦙  Starting Ollama…"
 $ENGINE run -d "${PLATFORM_OPTS[@]}" --name ollama-server \
   --network llama-net \
   -p "${OLLAMA_PORT}:${OLLAMA_PORT}" \
-  ollama/ollama > /dev/null 2>&1
+  docker.io/ollama/ollama > /dev/null 2>&1
 
 if ! wait_for_service "http://localhost:${OLLAMA_PORT}/" "Ollama" "$WAIT_TIMEOUT" "Ollama daemon"; then
   log "❌  Ollama daemon did not become ready in ${WAIT_TIMEOUT}s; dumping container logs:"