Document a removal timeline for strict_http=False compatibility mode

[Mattsface]

Why

Feedback on the 1.0 documentation pointed out that strict_http=False is described as a temporary migration opt-out, but the project does not currently state when that compatibility mode is expected to be removed.

Without a target release or deprecation policy, users cannot easily judge whether they should migrate immediately or whether they can reasonably remain on compatibility mode for a while.

What to decide

• Define whether strict_http=False has a planned removal release
• If removal is planned, document the target version or version range
• If the exact release is not yet known, document a clear minimum support/deprecation policy instead
• Make the wording consistent across the README, HTTP transport documentation, public API documentation, and relevant release notes
• Clarify what users should migrate to before compatibility mode is removed

Compatibility considerations

Removing strict_http=False would be a breaking change, so any removal plan should align with the project's 1.x compatibility guarantees and semantic versioning policy.

Acceptance criteria

• A documented deprecation/removal policy exists for strict_http=False
• Users can tell how long compatibility mode is expected to remain available
• Migration guidance clearly explains the recommended long-term behavior
• Current documentation uses consistent wording about the compatibility mode lifecycle

Feedback source: Reddit discussion about the 1.0 documentation.