chore: add community standards files; remove stray BRIEFING.md

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,106 @@
+name: Bug report
+description: Report a defect or unexpected behavior in diff-diff
+title: "[Bug]: "
+labels: ["bug"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to file a bug report. Please fill out the
+        sections below so the maintainer can reproduce the issue quickly.
+
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: A clear and concise description of the bug.
+      placeholder: When I call `DifferenceInDifferences.fit(...)` with ..., the result has ...
+    validations:
+      required: true
+
+  - type: textarea
+    id: reproducer
+    attributes:
+      label: Minimal reproducer
+      description: |
+        Smallest possible code snippet that reproduces the issue. Inline data is
+        ideal; if you must attach a file, please scrub any sensitive content.
+      render: python
+      placeholder: |
+        import numpy as np
+        import pandas as pd
+        from diff_diff import DifferenceInDifferences
+
+        df = pd.DataFrame({...})
+        est = DifferenceInDifferences()
+        results = est.fit(df, outcome='y', treatment='treated', time='post')
+        print(results.att)
+    validations:
+      required: true
+
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected behavior
+      description: What did you expect to happen?
+    validations:
+      required: true
+
+  - type: textarea
+    id: actual
+    attributes:
+      label: Actual behavior
+      description: What actually happened? Include the full traceback if applicable.
+      render: shell
+    validations:
+      required: true
+
+  - type: input
+    id: version
+    attributes:
+      label: diff-diff version
+      description: Output of `python -c "import diff_diff; print(diff_diff.__version__)"`
+      placeholder: "3.3.1"
+    validations:
+      required: true
+
+  - type: input
+    id: python-version
+    attributes:
+      label: Python version
+      placeholder: "3.11"
+    validations:
+      required: true
+
+  - type: dropdown
+    id: backend
+    attributes:
+      label: Backend
+      description: |
+        Run `python -c "from diff_diff import HAS_RUST_BACKEND; print(HAS_RUST_BACKEND)"`
+      options:
+        - "Rust (HAS_RUST_BACKEND=True)"
+        - "Pure Python (HAS_RUST_BACKEND=False)"
+        - "Not sure"
+    validations:
+      required: true
+
+  - type: dropdown
+    id: os
+    attributes:
+      label: Operating system
+      options:
+        - macOS (Apple Silicon)
+        - macOS (Intel)
+        - Linux (x86_64)
+        - Linux (aarch64)
+        - Windows
+        - Other
+    validations:
+      required: true
+
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional context
+      description: Anything else that might be relevant — relevant references, similar issues, workarounds you tried, etc.

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,64 @@
+name: Feature request
+description: Suggest a new estimator, diagnostic, or capability
+title: "[Feature]: "
+labels: ["enhancement"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for suggesting a feature. The maintainer prioritizes additions
+        that have a clear methodological foundation (paper, R package, or
+        established convention) and a concrete use case.
+
+  - type: textarea
+    id: use-case
+    attributes:
+      label: Use case
+      description: |
+        What problem are you trying to solve? Describe the analysis, design, or
+        workflow that motivates this request.
+      placeholder: |
+        I'm running a staggered DiD on retailer-week panel data with treatment
+        intensity that varies continuously, and I currently have to ...
+    validations:
+      required: true
+
+  - type: textarea
+    id: proposed-api
+    attributes:
+      label: Proposed API or behavior
+      description: |
+        Sketch what calling the feature would look like. A code example is
+        ideal, even if rough.
+      render: python
+    validations:
+      required: true
+
+  - type: textarea
+    id: references
+    attributes:
+      label: Methodology references
+      description: |
+        If this implements a published method, link to the paper(s) and/or any
+        existing R / Python implementation. Estimator additions generally need
+        a paper citation.
+      placeholder: |
+        - Paper: Author et al. (Year), "Title", Journal. DOI / arXiv link.
+        - Existing implementation: e.g. R package `did`, function `att_gt()`
+    validations:
+      required: false
+
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives considered
+      description: |
+        What workarounds exist today? Why aren't they sufficient?
+    validations:
+      required: false
+
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional context
+      description: Anything else relevant — related estimators in diff-diff, scope concerns, etc.

.gitignore

@@ -98,3 +98,7 @@ analysis/
 # Replication data (local only, not for distribution)
 replication_data/
 _scratch/
+
+# Per-initiative briefing notes (local only, not for distribution)
+BRIEFING.md
+briefings/

CODE_OF_CONDUCT.md

@@ -0,0 +1,83 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our community a harassment-free experience for everyone, regardless of age, body size, visible or invisible disability, ethnicity, sex characteristics, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, caste, color, religion, or sexual identity and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming, diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes, and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of acceptable behavior and will take appropriate and fair corrective action in response to any behavior that they deem inappropriate, threatening, offensive, or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, and will communicate reasons for moderation decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when an individual is officially representing the community in public spaces. Examples of representing our community include using an official e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event.
+
+## Enforcement
+
+Instances of unacceptable behavior may be reported to the project maintainer via GitHub at [@igerber](https://github.com/igerber). All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing clarity around the nature of the violation and an explanation of why the behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, for a specified period of time. This includes avoiding interactions in community spaces as well as external channels like social media. Violating these terms may lead to a temporary or permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public communication with the community for a specified period of time. No public or private interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, is allowed during this period. Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community standards, including sustained inappropriate behavior, harassment of an individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within the community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 2.1, available at [https://www.contributor-covenant.org/version/2/1/code_of_conduct.html][v2.1].
+
+Community Impact Guidelines were inspired by [Mozilla's code of conduct enforcement ladder][Mozilla CoC].
+
+For answers to common questions about this code of conduct, see the FAQ at [https://www.contributor-covenant.org/faq][FAQ]. Translations are available at [https://www.contributor-covenant.org/translations][translations].
+
+[homepage]: https://www.contributor-covenant.org
+[v2.1]: https://www.contributor-covenant.org/version/2/1/code_of_conduct.html
+[Mozilla CoC]: https://github.com/mozilla/diversity
+[FAQ]: https://www.contributor-covenant.org/faq
+[translations]: https://www.contributor-covenant.org/translations