feat: docs restructure, show_versions, pyright CI, remove 1e-10 zero guards (#6)

* feat(ci): add pyright static type checking

- Fix 4 pyright errors in factor.py (hash annotation, eq/ne override, dead code)
- Add pyright to CI pipeline and dev dependencies
- Remove _resolve_other (dead code after _binary refactor)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* docs: add pyright to all checklists and update changelog for 0.4.0

- PR template: add pyright check item
- README Development section: add pyright command
- CONTRIBUTING: add pyright to verify, dev cycle, and pre-PR checklist
- CHANGELOG [Unreleased]: full list of additions and changes since 0.3.0

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: quantbai

.github/pull_request_template.md

@@ -18,6 +18,7 @@
 - [ ] Added or updated tests
 - [ ] All tests pass (`pytest tests/ -v`)
 - [ ] Lint passes (`ruff check elvers/`)
+- [ ] Type check passes (`pyright elvers/`)
 
 ## New Operator Checklist
 <!-- Delete this section if not adding a new operator -->

.github/workflows/ci.yml

@@ -19,4 +19,5 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - run: pip install -e ".[dev]"
       - run: ruff check elvers/
+      - run: pyright elvers/
       - run: pytest tests/ -v

CHANGELOG.md

@@ -7,8 +7,19 @@ Numerical changes are marked with [NUMERICAL].
 
 ## [Unreleased]
 
+### Added
+- `show_versions()` for environment diagnostics in bug reports
+- Pyright static type checking in CI pipeline
+- Community templates: issue templates (bug, feature, new operator), CODE_OF_CONDUCT, SECURITY
+- CONTRIBUTING.md with workflow, numerical invariants, and design rationale
+- Timestamp type validation in loader (must be pl.Date or pl.Datetime)
+- `_check_intervals()` warns about irregular timestamp spacing
+
 ### Changed
-- [NUMERICAL] Removed arbitrary `1e-10` zero guards across all operators. Pure divisions (divide, inverse) now flow through Factor constructor (Inf → null). Statistical and regression operators use exact zero checks for degenerate cases (constant series). No more silent data loss from legitimate small values.
+- [NUMERICAL] Removed arbitrary `1e-10` zero guards across all operators. Pure divisions (divide, inverse) now flow through Factor constructor (Inf → null). Statistical and regression operators use exact zero checks for degenerate cases (constant series).
+- Replaced interval-based panel skeleton with union-based skeleton (no frequency inference)
+- Restructured documentation: CLAUDE.md (AI memo), CONTRIBUTING.md (human guide), no duplication
+- Removed `interval` parameter from `load()`
 
 ## [0.3.0] - 2026-03-24
 

CLAUDE.md

@@ -58,4 +58,3 @@ Data loading pipeline (each function has one responsibility):
 - `_validation.py`: not wired into all operator entry points
 - `_dev.py`: Python callbacks, not production-grade
 - No property-based testing or performance benchmarks
-- No static type checking (mypy/pyright) in CI; type hints are written but not enforced

CONTRIBUTING.md

@@ -22,6 +22,7 @@ Verify:
 ```bash
 pytest tests/ -v
 ruff check elvers/
+pyright elvers/
 ```
 
 ---
@@ -45,7 +46,7 @@ All changes enter through pull requests to `dev`.
 git checkout dev && git pull upstream dev       # 1. sync
 git checkout -b feature/ts-entropy              # 2. branch
 # ... implement ...
-ruff check elvers/ && pytest tests/ -v          # 3. verify
+ruff check elvers/ && pyright elvers/ && pytest tests/ -v  # 3. verify
 git add <specific files>                        # 4. stage (never git add -A)
 git commit -m "feat(ops): add ts_entropy"       # 5. commit
 git push -u origin feature/ts-entropy           # 6. push
@@ -89,6 +90,7 @@ Add entry to [OPERATORS.md](OPERATORS.md).
 ### 6. Pre-PR Checklist
 
 - [ ] `ruff check elvers/` passes
+- [ ] `pyright elvers/` passes
 - [ ] `pytest tests/ -v` passes (full suite)
 - [ ] Operator in `__init__.py` exports and `__all__`
 - [ ] Docstring: description, parameters, return type, null behavior, warmup
@@ -126,6 +128,7 @@ Full conventions: [OPERATORS.md](OPERATORS.md).
 ## Style
 
 - Ruff for formatting and linting (line-length = 120)
+- Pyright for static type checking (zero errors required in CI)
 - English for all code, comments, commits, and documentation
 - No emoji
 

README.md

@@ -80,6 +80,7 @@ Full specifications: **[OPERATORS.md](OPERATORS.md)**
 pip install -e ".[dev]"
 pytest tests/ -v
 ruff check elvers/
+pyright elvers/
 ```
 
 See [CONTRIBUTING.md](CONTRIBUTING.md) for the contributor guide.

elvers/core/factor.py

@@ -18,7 +18,7 @@ class Factor:
     """
 
     __slots__ = ("_df", "_name")
-    __hash__ = None
+    __hash__: None  # type: ignore[assignment]  # Unhashable by design: __eq__ returns Factor
 
     def __init__(self, df: pl.DataFrame, name: str):
         required = {"timestamp", "symbol", "factor"}
@@ -54,21 +54,15 @@ def __repr__(self) -> str:
         preview_df = self._df.sort(["timestamp", "symbol"])
         return f"Factor({self._name}, rows={len(self._df)})\n{preview_df.__repr__()}"
 
-    def _resolve_other(self, other: Factor | int | float):
+    def _binary(self, other: Factor | int | float, op, op_sym: str) -> Factor:
         if isinstance(other, Factor):
             left = self._df.rename({"factor": "_l"})
             right = other._df.select(["timestamp", "symbol", pl.col("factor").alias("_r")])
             merged = left.join(right, on=["timestamp", "symbol"], how="inner")
-            return merged, "_l", "_r", other._name
-        return self._df, "factor", None, str(other)
-
-    def _binary(self, other, op, op_sym) -> Factor:
-        if isinstance(other, Factor):
-            merged, lc, rc, oname = self._resolve_other(other)
             result = merged.with_columns(
-                op(pl.col(lc), pl.col(rc)).alias("factor")
+                op(pl.col("_l"), pl.col("_r")).alias("factor")
             ).select(["timestamp", "symbol", "factor"])
-            return Factor(result, f"({self._name}{op_sym}{oname})")
+            return Factor(result, f"({self._name}{op_sym}{other._name})")
         result = self._df.with_columns(
             op(pl.col("factor"), pl.lit(other)).alias("factor")
         )
@@ -142,8 +136,8 @@ def __lt__(self, other):
     def __le__(self, other):
         return self._binary(other, lambda a, b: a <= b, "<=")
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> Factor:  # type: ignore[override]  # Element-wise, not scalar bool
         return self._binary(other, lambda a, b: a == b, "==")
 
-    def __ne__(self, other):
+    def __ne__(self, other) -> Factor:  # type: ignore[override]  # Element-wise, not scalar bool
         return self._binary(other, lambda a, b: a != b, "!=")

pyproject.toml

@@ -44,6 +44,7 @@ version = {attr = "elvers.__version__"}
 dev = [
     "pytest>=7.0",
     "ruff>=0.4.0",
+    "pyright>=1.1",
     "pre-commit>=3.0",
 ]