Two cleanups from the hard-coded-vs-cascade audit:
#2 Centralize the canonical slot names. The lists {ssr,mdl,rsk,working,
staging,reviewing} and the per-party {incoming,received,issued,mdl,rsk,
working,staging,reviewing} were hand-written across ensure.go (×2),
fileapi.go (×2), virtualviews.go, lookups.go. New internal/zddc/slots.go is
the single registry with IsRowSlot/IsFolderNavSlot/IsVirtualAggregatorSlot/
IsPerPartySlot; virtualViewRE is built from it. Slot NAMES stay hard-coded
(they carry bespoke behavior) but now live in one place — adding/adjusting a
slot is one edit, not a hunt. Pure refactor; behavior unchanged.
#1 Make the history file-type selection cascade-driven. IsTextHistoryCandidate
hard-coded ".md"; now it matches the effective history_globs from the .zddc
cascade (default ["*.md"], widen per-deployment e.g. ["*.md","*.txt"]). New
ZddcFile.HistoryGlobs + mergeOverlay + PolicyChain.EffectiveHistoryGlobs +
HistoryGlobsAt, threaded through serveFilePut/serveFileMove/dispatch and
ServeTextHistory (now takes fsRoot). The history: bool still gates whether
snapshots are recorded; history_globs only says which file types qualify.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>