Add dynamic docs versioning, VQC sensitivity experiment, and minor fixes

Docs versioning:
- Add MkDocs on_config hook that reads the package version from
  setuptools-scm (_version.py or installed package) and injects it
  into the template context, replacing the hardcoded v0.1 badge.
- Strip dev/local suffixes so the docs always display the last
  tagged release (e.g. 0.3.1.dev1+g... -> 0.3.0).
- Add fetch-depth: 0 to CI docs job for correct version resolution.

VQC sensitivity experiment (Stage 6a.5):
- Grid search over learning rates and variational layers for angle
  and IQP encodings on moons/circles datasets.
- Checkpoint-based crash-safe resume, deterministic seed strategy,
  and JSON report with per-cell statistics and analysis summary.
- Comprehensive mocked test suite (tests/unit/experiments/).

Minor:
- Add paper/ to .gitignore.
- Switch PyPI badge to shields.io in README.
- Batch instantiation timings in test_performance for stability.

Author: ashutoshm1771

.github/workflows/ci.yml

@@ -150,6 +150,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
 
       - name: Set up Python
         uses: actions/setup-python@v5

.gitignore

@@ -71,6 +71,9 @@ experiments/plotting_journal.py
 # Verification folder (temporary)
 verification/
 
+# Paper (private drafts)
+paper/
+
 # OS
 .DS_Store
 Thumbs.db

README.md

@@ -4,7 +4,7 @@
 
 **The comprehensive library for quantum data encodings in machine learning**
 
-[![PyPI version](https://badge.fury.io/py/encoding-atlas.svg)](https://pypi.org/project/encoding-atlas/)
+[![PyPI version](https://img.shields.io/pypi/v/encoding-atlas.svg)](https://pypi.org/project/encoding-atlas/)
 [![Python versions](https://img.shields.io/pypi/pyversions/encoding-atlas.svg)](https://pypi.org/project/encoding-atlas/)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![CI](https://img.shields.io/github/actions/workflow/status/encoding-atlas/quantum-encoding-atlas/ci.yml?branch=master&logo=github&label=CI)](https://github.com/encoding-atlas/quantum-encoding-atlas/actions/workflows/ci.yml)

docs/hooks/version_hook.py

@@ -0,0 +1,61 @@
+"""MkDocs hook to inject the package version into template context."""
+
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+
+def _strip_dev_suffix(version: str) -> str:
+    """Strip setuptools-scm dev/local suffixes to show the last release version.
+
+    Examples: '0.3.1.dev1+gbd09888de' -> '0.3.0', '0.3.0' -> '0.3.0'
+    """
+    match = re.match(r"(\d+\.\d+\.\d+)", version)
+    if match:
+        base = match.group(1)
+        # If this is a dev version (e.g. 0.3.1.dev1), the base patch was
+        # bumped by setuptools-scm; roll it back to the actual tagged release.
+        if ".dev" in version:
+            major, minor, patch = base.split(".")
+            patch = str(max(int(patch) - 1, 0))
+            return f"{major}.{minor}.{patch}"
+        return base
+    return version
+
+
+def _read_version() -> str:
+    """Read version from _version.py or the installed package."""
+    raw = None
+
+    # Try 1: Read from source tree (editable install / local dev)
+    version_file = (
+        Path(__file__).resolve().parents[2] / "src" / "encoding_atlas" / "_version.py"
+    )
+    if version_file.exists():
+        match = re.search(
+            r'__version__\s*=\s*version\s*=\s*["\']([^"\']+)["\']',
+            version_file.read_text(),
+        )
+        if match:
+            raw = match.group(1)
+
+    # Try 2: Import from installed package (non-editable pip install in CI)
+    if raw is None:
+        try:
+            from encoding_atlas._version import __version__
+
+            raw = __version__
+        except ImportError:
+            pass
+
+    if raw is None:
+        return "dev"
+
+    return _strip_dev_suffix(raw)
+
+
+def on_config(config, **kwargs):
+    """Inject package_version into extra config for Jinja2 templates."""
+    config["extra"]["package_version"] = _read_version()
+    return config