docs(R5): rewrite knowledge schema + llm-wiki for DB-native model; deprecate root inventory.yaml

Rewrote .agents/domains/knowledge/schema.md and .agents/shared/llm-wiki.md
which described the deleted Python substrate (bin/homelab, oikos/cards/,
oikos/ledger.py, root inventory.yaml, knowledge/sources/, get_page/
search_docs MCP tools). Now reflect ADR 0003: Postgres DB is the single
source of truth for structured data and narrative knowledge; seeds/*.yaml
are bootstrap+DR manifests (content-hashed via seed_versions); archive/
knowledge/ is the frozen legacy wiki; MCP search_knowledge/get_entity_
knowledge replace get_page/search_docs.

Swept substrate refs in .agents/shared/{writing-style,page-templates}.md
and .agents/domains/operations/schema.md: bare inventory.yaml ->
seeds/inventory.yaml; knowledge/sources/ -> archive/knowledge/sources/
(historical); get_changelog/oikos/ledger.py -> DB audit trail / structured
document changelog field; HERMES -> Nomos.

Root inventory.yaml (618-line Python-era file superseded 2026-07-07 by
seeds/inventory.yaml) replaced with a deprecation stub pointing to the seed
and DB. Kept as a stub rather than deleted because AGENTS.md §1/§2 still
point clients at /opt/homelab-context/inventory.yaml; full on-client path
reconciliation deferred to R13.

Flagged export gap: oikos export regenerates seeds/{ontology,inventory,
policy}.yaml but NOT seeds/knowledge.yaml — API-added knowledge lives only
in the DB until hand-edited into the seed.

VERSION 0.7.7 -> 0.7.8. Plan R5 marked done.

.agents/shared/llm-wiki.md

@@ -1,40 +1,49 @@
 # LLM Wiki — the documentation contract
 
-How the narrative documentation in this repo is organized. The pattern is borrowed from the
-`sources / wiki / index / log` model: a durable synthesized layer (`archive/knowledge/`) built on top
-of immutable evidence (`knowledge/sources/`, incident records), with pure-listing indexes and an
-append-only operations log.
+How documentation in this repo is organized. The pattern is the `sources / wiki / index / log`
+model: a durable synthesized layer built on top of immutable evidence, with pure-listing indexes and
+an append-only operations log.
 
-This contract governs the **narrative layer only**. The machine-readable substrate — `inventory.yaml`,
-`secrets/`, `scripts/`, `bin/` — is not part of the wiki and never
-moves under it. See [the knowledge schema](../domains/knowledge/schema.md) for the split.
+This contract governs the **narrative layer only**. The machine-readable source of truth — the
+Postgres database, bootstrapped from `seeds/` — is not part of the wiki and never moves under it.
+See [the knowledge schema](../domains/knowledge/schema.md) for the split, and ADR 0003 for the
+DB-native model.
 
 ## Layers
 
-- **Sources** are immutable raw material: incident records (`knowledge/sources/investigations/`), external reference
-  docs (`knowledge/sources/references/`), and the live system itself (`pct config`, `docker inspect`).
-  Read them; do not rewrite them into other sources.
-- **Wiki** (`archive/knowledge/`) is the synthesized, authoritative current-state layer: one page per
-  node (`containers/`, `vms/`, host narratives) and per cross-cutting system (`infrastructure/`). A
-  reader understands the topic from the wiki page without reading the sources.
+- **Source of truth** is the Postgres database. Structured data (entities, relationships, status,
+  metrics) and narrative knowledge (documents, investigations, runbooks) both live there, in the
+  `entities` / `relationships` / `knowledge_entities` tables. It is bootstrapped at deploy time from
+  `seeds/{ontology,inventory,policy,knowledge}.yaml` (idempotent, content-hashed via
+  `seed_versions`) and mutated at runtime via the API/MCP. `oikos export` regenerates
+  `seeds/{ontology,inventory,policy}.yaml` for version control.
+- **Sources** are immutable raw material: incident records (now `investigation` entities in the DB,
+  historically `archive/knowledge/sources/investigations/`), external reference docs, and the live
+  system itself (`pct config`, `docker inspect`). Read them; do not rewrite them into other sources.
+- **Wiki** — the synthesized, authoritative current-state layer. Today this is the set of
+  `document` entities in the DB (one per node and per cross-cutting system), queried via MCP
+  `search_knowledge` / `get_entity_knowledge`. The legacy file-based wiki is frozen at
+  `archive/knowledge/{hosts,containers,vms,infrastructure}/` for historical reference only.
 - **Index** (`index.md` / folder `README.md`) is a pure listing — every page in scope with a
   one-line summary, and nothing else. Anything the section wants to say up front goes into a page
   the index lists, not into the index.
-- **Log** (`log.md`) is append-only, recording *doc-maintenance operations* (restructures, source
-  ingests, lint sweeps) in single-line format: `## [YYYY-MM-DD] <op> | <summary>`.
+- **Log** is append-only, recording *doc-maintenance operations* (restructures, source ingests,
+  lint sweeps) in single-line format: `## [YYYY-MM-DD] <op> | <summary>`. The active log is the DB
+  audit trail; `archive/knowledge/log.md` is the frozen legacy equivalent.
 
 ## Two logs, kept distinct
 
-- **`## Changelog`** on each node/topic page records *infrastructure* changes to that node. It is
-  machine-parsed (`get_changelog`, the Oikos ledger) — keep the `### YYYY-MM-DD — title` shape.
-- **`log.md`** per area records *documentation* operations only. It never duplicates the Oikos
-  change ledger (`oikos/ledger.py`), which stays authoritative for infra changes with
-  who/what/risk/approval/verification.
+- **`## Changelog`** on each node/topic document records *infrastructure* changes to that node. It
+  is stored as a structured field on the `document` entity — keep the `### YYYY-MM-DD — title`
+  shape so it parses cleanly.
+- **Doc-maintenance logs** record *documentation* operations only. They never duplicate the
+  infrastructure changelog, which stays authoritative for infra changes with
+  who/what/risk/approval/verification (now the DB audit trail, formerly `oikos/ledger.py`).
 
 ## Rules
 
 - Wiki pages stay short and focused. A page past ~300 lines splits.
-- Pages stay flat under `wiki/<section>/` until there are enough to warrant a sub-group.
+- Pages stay flat under their section until there are enough to warrant a sub-group.
 - Every page follows [writing-style.md](writing-style.md).
 - Plans and design docs always live in the repo `plans/` folder (`plans/YYYY-MM-DD-slug.md`),
   listed in `plans/index.md`, moved to `plans/done/` on completion — never a scratch path or a chat

.agents/shared/page-templates.md

@@ -14,7 +14,7 @@ in [writing-style.md](writing-style.md); the layer model (sources / wiki / index
 
 **Content / narrative pages:** lowercase-with-dashes, date-prefixed as needed
 
-- **Container pages:** `<id>-<name>.md` (e.g. `101-jellyfin.md`, `132-rclone.md`). The `<id>` is the LXC/VM ordinal from `inventory.yaml`.
+- **Container pages:** `<id>-<name>.md` (e.g. `101-jellyfin.md`, `132-rclone.md`). The `<id>` is the LXC/VM ordinal from the entity's attributes in the DB (seeded via `seeds/inventory.yaml`).
 - **Infrastructure / cross-cutting pages:** `<topic>.md` (e.g. `dns.md`, `auto-deploy.md`, `mesh.md`). Describes a system, not a specific node.
 - **Plans / investigations:** `YYYY-MM-DD-<slug>.md` (e.g. `2026-07-05-oikos-prometheus-lxc.md`). Date-sorted; slug is lowercase.
 - **Section indices:** `README.md` (lowercase, conventional). Prefer in folders; `index.md` only if both intro prose and listing coexist.
@@ -118,7 +118,7 @@ What it looks like after.
 Changelog entries to write, index status to update.
 ```
 
-### Investigation (`knowledge/sources/investigations/YYYY-MM-DD-slug.md`)
+### Investigation (`investigation` entity in the DB; historically `archive/knowledge/sources/investigations/YYYY-MM-DD-slug.md`)
 
 ```markdown
 # YYYY-MM-DD — <title>
@@ -152,16 +152,18 @@ Changelog entries to write, index status to update.
 ## Same-session update rule
 
 When you make a change to a node — migrate an LXC, update an IP, change a
-mount, deploy a new service — **update every relevant doc page in the same
-session.** A change that touches a container page must also update:
+mount, deploy a new service — **update the DB and every relevant doc page in
+the same session.** A change that touches a container must also update:
 
-- The `containers/index.md` table (IPs, host, mounts, status)
+- The `entities` / `relationships` rows for the node (via the API/MCP) —
+  this is the source of truth
+- The `document` entity's `at_glance` and `## Changelog` for the container
+- The `containers/index.md` table in the archived wiki (IPs, host, mounts,
+  status) — historical reference, update for consistency where still consulted
 - The `README.md` table (if the change affects listed columns)
 - The Caddy page site list (if the change affects `*.hubris.network` routing)
 - The DNS / ingress infrastructure pages (if the change affects routing)
 - The `hosts/{hubris,strong}.md` host page (if container count changes)
-- The `inventory.yaml` host entry (single source of truth)
-- The `infrastructure/topology.md` (generated from inventory, but regen if needed)
 
 The pattern of updating only one page and leaving stale references on others
 is a bug. If you're doing a multi-step migration, document the intermediate

.agents/shared/writing-style.md

@@ -36,7 +36,7 @@ Every doc-level page follows the same shape so a reader scans it in one pass.
 1. **One H1 = the page title.** Node pages use `# <id> — \`<name>\``; topic pages use `# <Topic>`.
 2. **Opening definition.** First paragraph, 1–3 sentences, says what the thing is. No motivation, no marketing, no setup.
 3. **Body sections** in the natural order for the topic. Reuse the section templates in [page-templates.md](page-templates.md).
-4. **`## Changelog`** at the bottom of every node/topic page — reverse-chronological, append-only. This section is machine-parsed (Go MCP `get_changelog` in `internal/mcp/server.go`); keep the `### YYYY-MM-DD — title` shape.
+4. **`## Changelog`** at the bottom of every node/topic page — reverse-chronological, append-only. This section is stored as a structured field on the `document` entity in the DB; keep the `### YYYY-MM-DD — title` shape so it parses cleanly.
 5. **Related links** only at the bottom, only when a reference cannot be woven inline.
 
 ## Section indexes (folder READMEs)
@@ -53,12 +53,12 @@ duplicated prose, no narrative between the intro and the table.
 - Prefer **tables** for enumerable items with internal structure (service/port maps, field lists, status grids). Reserve bullets for short non-structured lists.
 - Use the **bold-leading-phrase pattern** for structured points: `**Read-only by construction.** The MCP server never mutates state.` — a bold noun phrase, a period, then the explanation.
 - When enumerating across services or nodes, give each its own `###` sub-section or a table row, not one run-on paragraph.
-- Use backticks for code, paths, hostnames, and file names (`inventory.yaml`, `192.168.8.77`, `pct config`); italics for first-mention terminology.
+- Use backticks for code, paths, hostnames, and file names (`seeds/inventory.yaml`, `192.168.8.77`, `pct config`); italics for first-mention terminology.
 - Use `>` blockquotes for caveats and gaps that interrupt the main flow: `> **Outstanding gap.** DNS-vs-inventory drift check not yet wired.` One thought per blockquote.
 
 ## Diagrams
 
-- Mermaid is the default for topology and flow diagrams. `infrastructure/topology.md` is generated by `oikos/gen-topology.py` — do not hand-edit it. (Go DB-native topology generation planned.)
+- Mermaid is the default for topology and flow diagrams. `infrastructure/topology.md` in the archived wiki was generated by the retired `oikos/gen-topology.py`; the DB-native equivalent is a future task — do not hand-edit the archived file expecting it to regenerate.
 - ASCII box diagrams are fine for small shape diagrams; keep them to one screen.
 
 ## Sourcing and cross-references