kb: retire pi-installation association (OMP is the primary harness)

Purge live-state claims that ~/.pi is our harness; keep general
pi documentation in omp-docs/ and dated historical records.

- README.md: single config source; Legacy Notes reworded
- AGENTS.md: drop 'like ~/.pi did' framing
- APPEND_SYSTEM.md: okf-spec -> omp-docs/references/okf-spec.md
- dotfiles/zsh/.zshrc: systemprompt alias -> APPEND_SYSTEM.md
- managed skill llm-fleet-model-swap + model_config_sync skill:
  single-source models.yml; validation script YAML-only
- memories (MEMORY.md, memory_summary.md, learned.md): single source
- omp-docs: .okf root -> ~/.omp/omp-docs; de-live pi-era claims in
  pi/index.md, pi-web-access.md, engineering/agents-files.md

README.md

@@ -18,7 +18,7 @@ Dankware is the primary host — this repository lives at `~/.omp/` and drives t
 ~/.omp/
 ├── agent/              # OMP harness runtime
 │   ├── config.yml      # Live agent configuration
-│   ├── models.yml      # Model providers (imported from ~/.pi/agent/models.json)
+│   ├── models.yml      # Model providers (single source of truth)
 │   ├── APPEND_SYSTEM.md  # System prompt extensions
 │   ├── managed-skills/ # Managed skills (SKILL.md bundles)
 │   ├── models.db       # Model cache
@@ -68,8 +68,8 @@ Dankware is the primary host — this repository lives at `~/.omp/` and drives t
 - **OKF v0.1** — every doc file carries YAML frontmatter with a `type:` field. `index.md` files are directory listings (no frontmatter).
 - **Progressive disclosure** — `index.md` is a landing page; drill into subdirectories for detail.
 - **Verified facts** — stamped with `verified:` when probed against the live fleet. Trust over memory.
-- **Two config copies** — `~/.omp/agent/models.yml` is generated from `~/.pi/agent/models.json`. Edits touch both.
+- **Single config source** — `~/.omp/agent/models.yml` is the only model registry; OMP is the primary harness and there is no second copy to keep in sync.
 
 ## Legacy Notes
 
-The pi-era configuration at `~/.pi/` still exists for reference. Live harness config lives in `~/.omp/`. New managed skills live in `~/.omp/agent/managed-skills/` alongside legacy symlinked skills at `~/.pi/agent/skills/`.
+`omp-docs/pi/` and `omp-docs/core/` retain general documentation about the pi-coding-agent harness (its config format, packages, skill system) for reference. OMP at `~/.omp/` is the live harness; managed skills live in `~/.omp/agent/managed-skills/`.