Documents the reservation-based duplicate-injection guard introduced in v4.2.0 with accepted status, exported API signatures, release semantics, migration notes, and commit references. Closes MEDIUM-11
Documents the reservation-based duplicate-injection guard introduced in v4.2.0. Covers context (Issue #4012 race window), decision (Symbol token, post-dispatch hold, dispatch timeout, shared runner, prefix-tightened release), consequences (caller-side release discipline, AST audit strengthens enforcement), and references. Closes M11
Closes M11 Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
YeonGyu-Kim