A pure-Go indexer (go/ast for Go; line patterns for Swift, Rust, Python, JS/TS, C headers, shell, org and markdown headings) builds one symbol index per default-branch tree after a push, in a background worker: bounded by file size, name length, symbol count, bytes and time; built in chunks and swapped in so reads never see a partial build; a failure keeps the previous index and retries once. repo symbols searches it (paged), admin symbols reindex forces a rebuild; the blob view links names to their definition or a results page and lists a file's symbols. Migration. Parity/Users/CHANGELOG.
Closes #293