Replace paraphrased constitution with the 1224-line master.

Copy CODING_CONSTITUTION.md from the AgentStore docs/development path and split
the seven always-on .mdc files from that exact text.

.cursor/rules/30-rust.mdc

@@ -2,13 +2,93 @@
 alwaysApply: true
 ---
 
-# Periscope Cursor Engineering Rules
+# 33. RUST IS NOT A DEFAULT
 
-Mandatory for every Cursor agent working on Periscope. This section is copied from `docs/development/CODING_CONSTITUTION.md` and must not contradict that master.
+Rust must not be introduced simply because code is new.
 
-## 3. Rust
+Rust is justified only when there is a demonstrated engineering requirement.
+
+Valid reasons include:
+
+* measured performance bottleneck;
+* computationally intensive geometry;
+* large-scale spatial processing;
+* numerical computation;
+* graph processing;
+* memory pressure;
+* deterministic high-performance computation.
+
+Do not use Rust speculatively.
+
+---
+
+# 34. MEASURE BEFORE MOVING TO RUST
+
+Required sequence:
+
+```text
+correct implementation
+ ↓
+measurement
+ ↓
+profiling
+ ↓
+identified bottleneck
+ ↓
+Rust implementation
+ ↓
+benchmark
+ ↓
+accept/reject based on evidence
+```
+
+Do not introduce Rust based on assumptions about performance.
+
+---
+
+# 35. RUST BOUNDARIES MUST BE COARSE-GRAINED
+
+Prefer:
+
+```text
+Python
+   ↓
+structured input
+   ↓
+Rust engine
+   ↓
+structured result
+   ↓
+Python
+```
+
+Avoid excessive Python ↔ Rust calls for individual operations.
+
+Rust should encapsulate meaningful computational workloads.
+
+---
+
+# 36. DO NOT PREMATURELY FREEZE THE CORE IN RUST
+
+The semantic model should first become correct and well understood.
+
+Prefer:
+
+```text
+semantic model
+ ↓
+correctness
+ ↓
+tests
+ ↓
+architecture stabilization
+ ↓
+profiling
+ ↓
+Rust where justified
+```
+
+Do not rewrite the entire Periscope core in Rust simply to establish a Rust architecture.
+
+---
 
-- Periscope’s product code is Python/TypeScript today. If a Rust crate is added, it is original Periscope code, not a paste of an AGPL PinScope module.
-- Rust slices follow the same verify-then-switch rule: tests first, then wire into the Python/TS surface.
-- Use `rustfmt` + `clippy` on that crate. No `unsafe` without a comment that names the invariant.
-- Do not introduce Rust to dodge AGPL or to empty-delete Python in `dependency/`.