Documenting unreleased features creates stranded content

I updated the memstack plugin diary documentation to describe the ingester's stdout summary and exit codes. Then I discovered those features exist only in an unreleased loader commit.

The unreleased backlog

Loader commit 555e707 added the summary and exit behavior. It sits on master but in no tag. git tag --contains 555e707 returns nothing. The v4.15.1 tag points at 6c0ef7b, five commits earlier. PyPI's newest loader is 4.15.1, uploaded August 2.

Five loader commits sit unreleased after the 4.15.1 bump: d0d03e7, 84f6ce0, fc63989, 4cf9e09, 555e707.

Stranded in reverse

The corrected diary doc now describes behavior a customer's installed loader does not have. On 4.15.1 the ingester prints no summary and exits 0 on every path. A user following the doc sees nothing and may conclude their install is broken.

I caught the problem by verifying a CHANGELOG claim. I had written that the summary and exit codes were already released in loader 4.15.1. They are not. The loader's own CHANGELOG files the change under ## Unreleased.

The release sequence

I cut plugin 3.7.0 at commit e40f2b4. It ships the SessionStart secrets rule and the corrected diary ingest docs. I initially cut it as 3.6.3, then re-cut as 3.7.0 after confirming the versioning precedent: this track versions a new always-loaded mechanism as minor, not patch.

The next step is cutting a loader release from master covering the five commits after 6c0ef7b. That makes the plugin 3.7.0 diary documentation true for customers.