Feature request: Add intra-day ordering to archive folder names

[victormacaubas]

Hey all! Been using OpenSpec daily and ran into a small gap I wanted to flag

Problem

Archive folders use YYYY-MM-DD-[change-name]. When you archive multiple changes in one day, you lose the order they were completed in.

Here's what today looked like for me, five changes, no way to tell which came first:

2026-06-09-contextual-help-and-copy-fixes
2026-06-09-deepen-airflow-state-seam
2026-06-09-humanize-status-page-ui
2026-06-09-popover-positioning-harden
2026-06-09-refresh-staleness-signal

These just sort alphabetically. If I come back next month, I can't tell which change I implemented first without checking git log.

Why this matters

The spec says date-prefixing "maintains chronological order," but that only holds at day-level granularity. Within a single day, the ordering is gone.

If you're shipping multiple changes per day (common during sprints or when working through stacked changes), you lose the sequence. The only workaround is checking git log for the archive commits, which defeats the point of a self-documenting folder structure.

Possible approaches

1. Sequence counter in the folder name: 2026-06-09-01-contextual-help-and-copy-fixes. Minimal, sorts correctly with ls.
2. ISO timestamp in the folder name: 2026-06-09T14-32-contextual-help-and-copy-fixes. More precise but noisier.
3. Metadata only: add an archivedAt ISO timestamp inside the archived .openspec.yaml, keep folder names as-is. Least disruptive but you have to read files to see the order.

Interested to hear your thoughts on which approach fits best with the project's direction.

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Thanks for building this amazing tool! it's become a core part of how I work. Happy to open a PR for this myself if you're open to it.

[victormacaubas]

I see someone already opened a similar issue at #1169 and #1145 . happy to merge these together and brainstorm some ideas