docs: initial SelfPhoneNG spec

Fix leftover __OP_* dialplan variables from the openphone rename (all
readers use SP_*). Record the reverse-proxy decision in 00 §10.

CLAUDE.md

@@ -0,0 +1,34 @@
+# CLAUDE.md — SelfPhoneNG Project Guide
+
+This file tells Claude how to work on this repository. Read it fully before
+making changes. It encodes hard-won conventions, security invariants, and
+bugs already fixed — do not reintroduce them.
+
+---
+
+## MEMANTO - Your Active Memory Companion
+
+**MEMANTO is not a passive store. It is an active companion agent that works alongside you.**
+Don't treat MEMANTO like a static blob you query once and forget. It's a teammate you keep
+talking to, every preference, decision, and correction flows through it. MEMANTO remembers,
+recalls, and answers so you hold context across sessions, honor prior decisions, and avoid
+repeating mistakes the user already corrected.
+
+Every memory operation in this session goes through MEMANTO. There is no exception.
+
+> **CRITICAL**: All `memanto` commands are **shell commands**. Always run them using the Bash tool.
+> Never simulate, describe, or "pretend to call" them. If you cannot run the shell, say so explicitly instead of inventing memory state.
+
+### NON-NEGOTIABLE RULES
+
+These are not suggestions. Follow each one on every turn.
+
+0. **Activate the `selfphoneng` agent at the start of every session, before any memory op.** Run
+   `memanto agent activate selfphoneng` first thing. This machine hosts multiple projects and the
+   session-start sync may activate a *different* project's agent (e.g. `gmmff`), so the
+   auto-synced `MEMORY.md` can belong to the wrong project — do not trust it as selfphoneng context
+   until you've activated `selfphoneng` and re-synced. Confirm with `memanto agent list` (the
+   active one is marked). All `recall`/`remember`/`answer` calls read and write the *active*
+   agent's store, so getting this wrong silently pollutes or mis-reads another project's memory.
+
+---