chore: bump minimum Python to 3.10 and upgrades Black to 26.3.1

[danielmeppiel]

Summary

Raises the minimum Python version from 3.9 to 3.10 and upgrades Black to 26.3.1.

Why Dependabot couldn't fix this

Black 26.3.1 (the patched version) requires Python >=3.10. Since the project declared requires-python = ">=3.9", Dependabot couldn't find a single version satisfying both constraints — it was capped at 25.11.0.

Changes

• pyproject.toml: requires-python bumped from >=3.9 to >=3.10
• uv.lock: Black upgraded 25.1.0 → 26.3.1 (also simplified — no more multi-fork resolution needed)
• Docs: Updated Python version references in key-concepts.md and agent-workflows.md

Justification

• Python 3.9 reached end-of-life in October 2025 (5 months ago)
• CI already targets Python 3.12 exclusively
• No known users running on 3.9

Resolves #17

[Copilot]

Pull request overview

This PR raises the project’s minimum supported Python version to enable upgrading Black to a patched release that requires Python >=3.10, and updates docs to reflect the new baseline.

Changes:

• Bump requires-python from >=3.9 to >=3.10 in packaging metadata.
• Update documentation references from Python 3.9+ to 3.10+.
• (Per PR description) Upgrade Black in the lockfile to address Dependabot alert #17.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 1 comment.

File	Description
pyproject.toml	Raises declared minimum Python version to 3.10+.
docs/src/content/docs/introduction/key-concepts.md	Updates “Key Technologies” Python version reference to 3.10+.
docs/src/content/docs/guides/agent-workflows.md	Updates runtime requirements table to Python 3.10+ for the LLM runtime.

Comments suppressed due to low confidence (2)

pyproject.toml:10

• Package classifiers still include "Programming Language :: Python :: 3.9" even though requires-python is now >=3.10. This makes the published metadata inconsistent/misleading. Remove the 3.9 classifier (and ensure classifiers reflect the supported versions).

requires-python = ">=3.10"

pyproject.toml:10

• The project now declares support for Python >=3.10, but CI and dev tooling are still hard-pinned to Python 3.12 (GitHub Actions PYTHON_VERSION=3.12; [tool.black].target-version = ["py312"]; [tool.mypy].python_version = "3.12"). If 3.10/3.11 are intended to be supported, add CI coverage for those versions and align tooling targets accordingly; otherwise consider bumping requires-python to match what is actually tested.

requires-python = ">=3.10"

[Copilot]

requires-python is now >=3.10, but the installer script still checks for and advertises Python 3.9+ (install.sh sets REQUIRED_VERSION="3.9" and prints "Python 3.9+ detected"). On systems with only Python 3.9, the installer may route to pip install apm-cli and then fail due to the new package requirement. Update install.sh (version check + user-facing messages) to require 3.10+ to match this change.

This issue also appears in the following locations of the same file:

• line 10
• line 10