feat: add self-update command and bump to 2.0.1

- Add `coinhunter update` CLI command for pipx/pip upgrade
- README: document update behavior and recommend pipx install
- Dynamic version badge with cacheSeconds=60
- Version bump: 2.0.0 → 2.0.1

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -11,7 +11,7 @@
 </p>
 
 <p align="center">
-  <a href="https://pypi.org/project/coinhunter/"><img src="https://img.shields.io/pypi/v/coinhunter?style=flat-square&color=F7B93E&labelColor=1a1a1a" /></a>
+  <a href="https://pypi.org/project/coinhunter/"><img src="https://img.shields.io/pypi/v/coinhunter?style=flat-square&color=F7B93E&labelColor=1a1a1a&cacheSeconds=60" /></a>
   <a href="#"><img src="https://img.shields.io/badge/python-3.10%2B-3776ab?style=flat-square&logo=python&logoColor=white&labelColor=1a1a1a" /></a>
   <a href="#"><img src="https://img.shields.io/badge/tests-passing-22c55e?style=flat-square&labelColor=1a1a1a" /></a>
   <a href="#"><img src="https://img.shields.io/badge/lint-ruff%20%2B%20mypy-8b5cf6?style=flat-square&labelColor=1a1a1a" /></a>
@@ -21,11 +21,25 @@
 
 ## Install
 
+For end users, install from PyPI with [pipx](https://pipx.pypa.io/) (recommended) to avoid polluting your system Python:
+
 ```bash
-pip install -e ".[dev]"
+pipx install coinhunter
 coinhunter --help
 ```
 
+Check the installed version:
+
+```bash
+coinhunter --version
+```
+
+To update later:
+
+```bash
+pipx upgrade coinhunter
+```
+
 ## Initialize runtime
 
 ```bash
@@ -73,8 +87,13 @@ coinhunter trade futures close BTCUSDT
 coinhunter opportunity portfolio
 coinhunter opportunity scan
 coinhunter opportunity scan --symbols BTCUSDT ETHUSDT SOLUSDT
+
+# Self-update
+coinhunter update
 ```
 
+`update` will try `pipx upgrade coinhunter` first, and fall back to `pip install --upgrade coinhunter` if pipx is not available.
+
 ## Architecture
 
 CoinHunter V2 uses a flat, direct architecture:
@@ -106,6 +125,16 @@ Events include:
 
 ## Development
 
+Clone the repo and install in editable mode:
+
+```bash
+git clone https://git.tacitlab.cc/TacitLab/coinhunter-cli.git
+cd coinhunter-cli
+pip install -e ".[dev]"
+```
+
+Run quality checks:
+
 ```bash
 pytest tests/           # run tests
 ruff check src tests     # lint