feat: D24 fact intervals (--as-of) and bin/stack assistant helpers. (#37)

Store valid_from/valid_to on leafs and filter search by calendar day without
overloading D16 source staleness; stack start/start-assistant wires brain + PicoClaw.

docs/README.md

@@ -18,9 +18,9 @@ Evidence-first knowledge graph. Facts need proof or they are
 | tutorial / howto | [runbook](runbook.md) — run anywhere (uv, Go, Docker) |
 | explanation | [design](design.md) — two roots, deduction, D17/D20/D18 |
 | explanation | [roadmap](roadmap.md) — gap to v1 (epic #16) |
-| howto | [picoclaw](picoclaw.md) — MCP agent profile |
+| howto | [picoclaw](picoclaw.md) — MCP agent (`bin/stack/start-assistant`) |
 | howto | [reasoner](reasoner.md) — CPU bake-off (D18) |
-| reference | [PLAN.md](../PLAN.md) — decisions D1–D22 |
+| reference | [PLAN.md](../PLAN.md) — decisions D1–D24 |
 
 Decisions the public face must name: **D3** SearXNG compose, **D6** Go service /
 Python write sidecar, **D14** `bin/{subject}/{method}.go`, **D15** Gitea origin,

docs/design.md

@@ -68,6 +68,15 @@ binary); conversion prints leafs, brain write is `bin/brain/index.go`.
 `bin/facts/audit stale` flags leafs whose observed revision is behind the
 corpus HEAD.
 
+Fact **interval of truth** (D24 / OQ5): leaf props `valid_from` /
+`valid_to` (YYYY-MM-DD, inclusive; empty end = open; both empty = legacy
+always-active). `bin/brain/search.go --as-of YYYY-MM-DD` and MCP/HTTP
+`as_of` keep hits whose interval covers that day. This is not D16
+`temporal_freshness` (source freshness vs HEAD). [#36](https://git.produktor.io/eSlider/2dph/issues/36).
+Existing `kb.lbug` without the columns: open/search/add runs an idempotent
+`ALTER TABLE Leaf ADD …` (no full rebuild required). Fresh `--rebuild` still
+creates them in `CREATE NODE TABLE`.
+
 ## Sources (auto-pairing)
 
 - A: runtime state — `docker ps` (container running), ports actually bound

docs/picoclaw.md

@@ -6,6 +6,18 @@ CPU reasoner. Default agent model is `qwen3.5:9b` (RAM path, D18). Weights stay
 in the reasoner volume, not in the 2dph image.
 No secrets in git: Ollama needs no key; MCP is local HTTP.
 
+```bash
+bin/stack/start-assistant
+bin/stack/start-assistant --no-attach
+bin/stack/start-assistant -- -m "search the 2dph brain for LadybugDB"
+bin/stack/status
+bin/stack/stop
+```
+
+`start-assistant` reuses a healthy brain on `:8630`, starts the CPU reasoner,
+pulls `qwen3.5:9b` if missing, brings up the gateway with `--no-deps picoclaw`,
+then `picoclaw agent` (MCP `search` → `get` → `audit`). Gateway-only Compose:
+
 ```bash
 docker compose --profile picoclaw up -d
 # already serving :8630 / :11435:

docs/roadmap.md

@@ -41,10 +41,12 @@ Epic [#16](https://git.produktor.io/eSlider/2dph/issues/16) closed.
 [#29](https://git.produktor.io/eSlider/2dph/issues/29) OQ1 contradiction
 resolution — **in** (`temporal_freshness`, `authority_pairing`).
 [#34](https://git.produktor.io/eSlider/2dph/issues/34) D23 flaggy CLI — **in**.
+[#36](https://git.produktor.io/eSlider/2dph/issues/36) OQ5/D24 fact intervals /
+as-of — **in** (not D16 `temporal_freshness`).
 
 ## Blockers
 
-None for epic #16 (closed). Remaining v2: OQ4.
+None for epic #16 (closed). Remaining v2: OQ4 (deferred).
 
 ```
 question
@@ -60,6 +62,8 @@ question
 ## Not v1
 
 OQ4 YAML-first leafs.
+OQ5/D24 fact intervals + as-of — **in**
+([#36](https://git.produktor.io/eSlider/2dph/issues/36)).
 OCR (OQ2), duckdb-go (OQ3/D22), and D16 adjudication (OQ1) are in.
 
 ## Close epic #16 when

docs/runbook.md

@@ -53,12 +53,15 @@ bin/brain/add.go --text "arc-1 runs Matrix" --root facts --source "compose.yml x
 bin/brain/index.go --rebuild --with-facts --with-chats
 bin/brain/search.go "LadybugDB vector index"     # facts → info → web (D17)
 bin/brain/search.go "upstream flag" --no-web
+bin/brain/search.go "who works where" --as-of 2025-01-01  # D24 intervals
 source <(./bin/cli/complete.go bash)            # D23 flaggy complete
 bin/brain/get.go <id> --body
 bin/brain/stats.go
 ```
 
-`--hop N` walks File → Commit → Person from each hit. Empty web results are `throttled`, not absence.
+`--hop N` walks File → Commit → Person from each hit. `--as-of YYYY-MM-DD`
+keeps leafs whose `valid_from`/`valid_to` cover that day (empty interval =
+legacy always-on). Empty web results are `throttled`, not absence.
 Gap to v1: [roadmap](roadmap.md) / [epic #16](https://git.produktor.io/eSlider/2dph/issues/16).
 
 Ladybug 0.19: never `DROP INDEX` FTS/VECTOR (ghost catalog). Fresh indexes =
@@ -66,6 +69,16 @@ delete `var/kb.lbug` then `--rebuild`.
 
 ## HTTP / MCP
 
+```bash
+bin/stack/start                 # brain :8630, wait until MCP search/get/audit
+bin/stack/status                # YAML: brain / reasoner / picoclaw
+bin/stack/start-assistant       # + qwen3.5:9b + PicoClaw agent (ask the brain)
+bin/stack/start-assistant --no-attach
+bin/stack/stop                  # compose stop; volumes kept
+```
+
+Same Compose services by hand:
+
 ```bash
 docker compose up -d brain                       # :8630 Zig CGO serve
 docker compose --profile index run --rm index    # rebuild
@@ -73,6 +86,7 @@ docker compose --profile picoclaw up brain-mcp   # MCP 127.0.0.1:8630
 ```
 
 `GET /openapi.json`, `POST /mcp`. Agent tool order: `search` → `get` → `audit`.
+See [picoclaw.md](picoclaw.md).
 
 ## Reasoner (optional, D18)