docs(v0.7.0): redraw hero/demo-flow/architecture with PAC (SVG)

Replaced 3 stale PNGs (from v0.3 era, 10 hooks) with SVGs that reflect
v0.7.0 architecture: 12 hooks, 5 layers, PAC as first-class feature.

- hero-banner.svg — new positioning line "The first AI plugin that
  speaks first" + 3 pillars (Learning / Forgetting / PAC) with PAC
  visually highlighted via accent gradient
- demo-flow.svg — two loops on one canvas: reactive error loop (top,
  neutral) and proactive PAC loop (bottom, accent) + actual PAC
  challenge output example
- architecture.svg — 5-layer stack with hook counts per layer; PAC
  layer marked NEW v0.7.0; storage row shows ~/.enso/pac/ alongside
  lessons/dikw/traces

SVG over PNG: scales crisply on any display, version-controllable,
easy to tweak in future without regenerating binaries. GitHub renders
SVG natively in README.

Author: amazinglvxw

README.md

@@ -1,5 +1,5 @@
 <p align="center">
-  <img src="docs/assets/hero-banner.png" alt="Enso" width="100%">
+  <img src="docs/assets/hero-banner.svg" alt="Enso" width="100%">
 </p>
 
 <p align="center">
@@ -34,7 +34,7 @@ Enso breaks that silence. It is a discipline plugin that adds three things no ma
 Install in 30 seconds. Just bash + python3 (pre-installed on macOS/Linux). Wraps around Claude Code, Hermes, OpenClaw, Gemini CLI. Your data stays local.
 
 <p align="center">
-  <img src="docs/assets/demo-flow.png" alt="Enso: Session 1 error -> Session 2 learned" width="85%">
+  <img src="docs/assets/demo-flow.svg" alt="Enso: Session 1 error -> Session 2 learned" width="85%">
 </p>
 
 ## Quickstart
@@ -193,7 +193,7 @@ Your Agent (Claude Code / Hermes / OpenClaw / Gemini CLI / ...)
 ## How It Works
 
 <p align="center">
-  <img src="docs/assets/architecture.png" alt="Enso Architecture" width="85%">
+  <img src="docs/assets/architecture.svg" alt="Enso Architecture" width="85%">
 </p>
 
 **12 hooks, 5 layers.** The agent can't skip what code enforces.

README.zh-CN.md

@@ -1,5 +1,5 @@
 <p align="center">
-  <img src="docs/assets/hero-banner.png" alt="Enso — 自进化 AI Agent 纪律系统" width="100%">
+  <img src="docs/assets/hero-banner.svg" alt="Enso — 自进化 AI Agent 纪律系统" width="100%">
 </p>
 
 <p align="center">
@@ -31,7 +31,7 @@ Enso 打破这个沉默。作为 AI Agent 的纪律插件，它提供三样主
 3. **🪞 PAC 主动问责挑战** —— AI 主动提出 *你自己没问* 的问题。
 
 <p align="center">
-  <img src="docs/assets/demo-flow.png" alt="Enso: 会话 1 犯错 → 会话 2 学会了" width="85%">
+  <img src="docs/assets/demo-flow.svg" alt="Enso: 会话 1 犯错 → 会话 2 学会了" width="85%">
 </p>
 
 ## 快速开始
@@ -176,7 +176,7 @@ Pre-tool-use Hook（自我保护、安全扫描、预算守护、写入验证）
 ## 怎么工作的
 
 <p align="center">
-  <img src="docs/assets/architecture.png" alt="Enso 架构" width="85%">
+  <img src="docs/assets/architecture.svg" alt="Enso 架构" width="85%">
 </p>
 
 **12 个 Hook，5 层生命周期。** 代码强制执行，Agent 无法跳过。