plans: five rose-ash subsystem plans + three loop briefings

Plans for acl-on-sx (Datalog), flow-on-sx (Scheme), feed-on-sx (APL),
mod-on-sx (Prolog), search-on-sx (Haskell). Each is a 4-phase queue
sitting on its respective guest language, targeting rose-ash needs:
access control, durable workflows, activity feeds, moderation, search.
Federation extension in Phase 4 of each (plugs into fed-sx).

Briefings for the three loops we're kicking off now: acl-loop,
flow-loop, feed-loop. mod-sx and search-sx briefings will follow
once the first three have surfaced any shared infrastructure
worth extracting to lib/guest/.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plans/acl-on-sx.md

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+# acl-on-sx: Access Control on Datalog
+
+rose-ash needs fine-grained, explainable, federation-aware access control. Subjects
+(users, groups, roles, services) × actions (read, edit, comment, moderate, federate)
+× resources (pages, posts, threads, peers). Decisions must come with a trace — not just
+permit/deny, but **why**.
+
+Datalog's bottom-up rule engine produces transparent permit/deny chains: the proof tree
+is the audit trail. Inheritance over groups + resource hierarchies is recursive Datalog
+in one rule. Federation extends naturally — fed-sx replicates ACL facts, peers reason
+over the union.
+
+End-state: a Datalog-on-SX layer specifically for ACL, with explanation API, audit log,
+and federation extension. Reuses `lib/datalog/` evaluator and term model where possible.
+
+## Status (rolling)
+
+`bash lib/acl/conformance.sh` → **0/0** (not yet started)
+
+## Ground rules
+
+- **Scope:** only touch `lib/acl/**` and `plans/acl-on-sx.md`. Do **not** edit `spec/`,
+  `hosts/`, `shared/`, `lib/datalog/**`, or other `lib/<lang>/`. You may **import**
+  from `lib/datalog/` (its public API in `lib/datalog/datalog.sx`); do **not** copy or
+  modify Datalog code.
+- **Shared-file issues** go under "Blockers" with a minimal repro; do not fix here.
+- **SX files:** use `sx-tree` MCP tools only.
+- **Architecture:** thin layer on top of `lib/datalog/`. Define schema, surface API,
+  audit + federation hooks. The rule engine itself is Datalog's.
+- **Watch for shared patterns** going into `lib/guest/` — both acl-sx and mod-sx need
+  rule-engine plumbing. If you find shared shape, flag it for extraction (don't
+  extract yet — wait for mod-sx to start).
+- **Commits:** one feature per commit. Keep Progress log updated and tick boxes.
+
+## Architecture sketch
+
+```
+ACL declarations (SX)            User query
+        │                            │
+        ▼                            ▼
+lib/acl/schema.sx             lib/acl/api.sx
+  — subject sorts                — (acl/permit? subj act res)
+  — resource sorts               — (acl/explain subj act res)
+  — action sorts                 — (acl/audit subj act res :allowed?)
+  — fact schema                       │
+        │                             ▼
+        ▼                       lib/acl/engine.sx
+lib/acl/facts.sx                  — builds Datalog query
+  — actor(id, kind)               — invokes lib/datalog/
+  — resource(id, kind)            — extracts proof tree
+  — member_of(actor, group)            │
+  — child_of(res, parent)              ▼
+  — grant(actor, act, res)        lib/acl/audit.sx
+  — deny (actor, act, res)          — persistent decision log
+                                    — query API
+```
+
+## Phase 1 — Direct grants
+
+- [ ] `lib/acl/schema.sx` — sorts: subject {user, group, role, service}, action,
+  resource {page, post, thread, peer}
+- [ ] `lib/acl/facts.sx` — `actor`, `resource`, `grant`, `deny` predicates as Datalog
+  EDB
+- [ ] `lib/acl/engine.sx` — `(permit? subj act res db)` reduces to Datalog query
+- [ ] `lib/acl/api.sx` — public `(acl/permit? ...)` taking implicit current db
+- [ ] `lib/acl/tests/direct.sx` — 15+ cases: direct grant, missing grant, explicit deny
+- [ ] `lib/acl/scoreboard.{json,md}` baseline
+- [ ] `lib/acl/conformance.sh` runs the suite
+
+## Phase 2 — Inheritance
+
+- [ ] `member_of(actor, group)` chain — group grants apply to members (transitive)
+- [ ] `child_of(res, parent)` chain — parent grants apply to children (transitive)
+- [ ] role expansion — role contains list of (action, resource) tuples
+- [ ] deny-overrides — explicit deny wins over inherited allow
+- [ ] `lib/acl/tests/inherit.sx` — 25+ cases: nested groups, deep resource trees,
+  conflict resolution, deny precedence
+- [ ] document the deny-overrides choice in plan
+
+## Phase 3 — Explanation + audit
+
+- [ ] `(acl/explain subj act res)` → `{:allowed? T :proof <tree>}`
+- [ ] proof tree extracts from Datalog's derivation
+- [ ] `lib/acl/audit.sx` — append-only decision log (in-memory + serializer for disk)
+- [ ] `(acl/audit-tail n)` for recent decisions
+- [ ] `lib/acl/tests/explain.sx` — proof correctness, audit completeness
+
+## Phase 4 — Federation
+
+- [ ] peer trust facts — `peer(addr, kind)`, `trust(peer, level)`
+- [ ] delegated grants — `delegate(peer, actor, action, resource)`
+- [ ] cross-instance permit chain — query asks local + queries trusted peers via fed-sx
+- [ ] revocation propagation — fact retraction across federation
+- [ ] `lib/acl/tests/fed.sx` — federated grant chains (mock fed-sx transport in tests)
+
+## Progress log
+
+(loop fills this in)
+
+## Blockers
+
+(loop fills this in)