chore: drop Python 3.10, add 3.15, and fix lint broken by ruff 0.16

[EarningsCall]

Summary

Fixes the red CI on master and updates the supported Python range.

Why CI broke

hatch run lint:all started failing on master (run 39155068553) with 129 ruff errors, with no code change. #46 touched only release.yml, which this workflow doesn't run.

• The lint env installs ruff without an upper bound (ruff>=0.0.166), and [tool.ruff.lint] never set select, so the rule set was whatever ruff ships as defaults.
• Ruff 0.16.0 (2026-07-23, two days after the last green run) expanded the default rule set (UP, I, PLR, TRY, LOG, …).
• Bisected on the same code: ruff 0.15.22 passes and every release from 0.16.0 to 0.17.1 fails.

Fix: pin select = ["E4", "E7", "E9", "F"], the previous defaults, so future ruff upgrades can't change the rule set.

The latest mypy (2.4.0) also reported a real type error that CI hadn't reached yet: response in do_get() is assigned both CachedResponse and requests.Response. It now has a requests.Response annotation.

Python versions

• Breaking: drop Python 3.10 (end of life since October 2026). requires-python = ">= 3.11", and CI's lint/coverage job moves to 3.11.
• Add Python 3.15 to the container test matrix and classifiers.
• Remove the Z-suffix workaround in _parse_conference_date(). datetime.fromisoformat() handles Z natively from 3.11, and the existing test still covers it.
• Bump version to 3.0.0 with a 2026-10-18 CHANGELOG entry, following Drop Python 3.8 and 3.9 support, require 3.10+ #42.

Test plan

• pytest on 3.11, 3.12, 3.13, 3.14, 3.15: 89 passed each
• hatch run all:test (container matrix, incl. python:3.15 image): all pass locally
• ruff 0.17.1 + 0.15.22, black 26.10.1, mypy 2.4.0: clean
• CI green

🤖 Generated with Claude Code

Summary by CodeRabbit

• Compatibility
  • Version 3.0.0 requires Python 3.11 or later. Python 3.10 is no longer supported.
  • Support now includes Python 3.15, alongside Python 3.11 through 3.14.

[coderabbitai]

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ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Repository: EarningsCall/coderabbit/.coderabbit.yaml
• Review profile: CHILL
• Plan: Essentials
• Run ID: 4dd66814-0b56-4b50-b860-38f3533d407c

📥 Commits

Reviewing files that changed from the base of the PR and between 3c0e997 and e0bb9b0.

📒 Files selected for processing: 1

• CHANGELOG.md

🚧 Files skipped from review as they are similar to previous changes: 1

• CHANGELOG.md

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📝 Walkthrough

The project now requires Python 3.11, tests Python 3.11–3.15, and reports version 3.0.0. CI, documentation, and tooling targets reflect this range. Runtime code adds a response annotation and changes conference date parsing.

Changes: Python support update

Layer / File(s)	Summary
Support contract and validation matrices pyproject.toml, hatch.toml, .github/workflows/test.yml, README.md, CLAUDE.md, CHANGELOG.md	The package requires Python 3.11, removes Python 3.10, adds Python 3.15, and updates the related CI matrices and documentation. The changelog adds the 3.0.0 release entry.
Tooling and lint targets pyproject.toml	Black and Ruff target Python 3.11. Ruff explicitly selects rule groups E4, E7, E9, and F.
Runtime code adjustments earningscall/api.py, earningscall/event.py	do_get annotates response as requests.Response. Conference dates pass directly to datetime.fromisoformat without trailing-Z rewriting.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~12 minutes

Change: Other

Merge Risk: ⚪ Minimal · up to e0bb9

No merge-blocking issue is established for this change; complete the normal validation before merging.

Pre-merge checks: 5

Check name	Status	Explanation
Docstring Coverage		Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files. (1 skipped: 1 …
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly summarizes the primary changes: dropping Python 3.10, adding Python 3.15, and fixing Ruff-related lint failures.

Full details: Docstring Coverage

Explanation

Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files. (1 skipped: 1 unsupported.)

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