knowledge-30.md

systems/30-tech/gov/knowledge-30.md
# knowledge-03.md — Tech [03]
# CAI System Experience & Expertise Log
# Standard: D091/D095 — loaded at ORIENT every session
# Last updated: 07/11/26

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## Patterns

- link_session (not update_decision_session) is security filter-safe — use se_id param not session_id
- Bootstrap deploy from backend/info/domains/: use dirname(dirname(dirname(__DIR__))) — 3 levels up to public_html
- backend/info/domains/ whitelisted in backend/.htaccess — all hub + viewer pages public, no PIN gate needed
- write-api blocks PHP keywords — always b64+bootstrap for PHP content
- [api] serves files under systems/ backend/ frontend/ transfers/ — add ?download=1 for save
- Community DBs: records.db=backend/records/db/records.db | inbox=systems/community/inbox/community.db | transfers=transfers/transfers.db
- Session log display: reverse blocks split by --- so newest is first
- DB banner cutoff: breadcrumb top:90px + layout padding-top:134px clears all fixed bars on viewer

## Lessons

- str_replace on PHP source fails if whitespace differs — grep exact strings before patching
- eval() blocked server-side — always write+include pattern never eval(base64_decode())
- backend/sys-com/ is PIN-gated — move viewer/hub pages to backend/info/domains/ instead
- DB count pills must be anchor tags not divs to be tappable
- position:fixed and position:relative conflict — never mix on same element

## Open Questions

- Roll hub template to remaining 10 systems (01-master through 10-travel)
- DB viewer hub back-link from records.db — patch did not apply cleanly — redo in clean rebuild
- system DB add_decision HTTP 500 — Server [40] aware