Improve container build reliability (#457)

* docker: add .env usage in build-container.sh
* .github,docker: add rocm, improve logging
* .github,CLAUDE.md: fix workflow and update guidelines

Update containers workflow to only push images when triggered
manually or on schedule, not on workflow file changes.

- add push trigger for workflow file changes in containers.yml
- update push condition to skip on regular push events
- update CLAUDE.md commit message guidelines

* docker: remove comma in build-container.sh

* .github,docker: improve container build workflow

Add pagination support for fetching llama.cpp tags and improve debugging.

- add build-container.sh to workflow trigger paths
- implement fetch_llama_tag() with pagination support
- replace .env with local testing instructions
- add DEBUG_ABORT_BUILD flag for testing

CLAUDE.md

@@ -12,7 +12,7 @@ llama-swap is a light weight, transparent proxy server that provides automatic m
 - when summarizing changes only include details that require further action
 - just say "Done." when there is no further action
 - use `gh` to create PRs and load issues
-- do not mention "created by claude" in commit messages
+- do include Co-Authored-By or created by when committing changes or creating PRs
 - keep PR descriptions short and focused on changes.
   - never include a test plan