* main: (21 commits)
  [ty] Literal promotion refactor (#20646)
  [ty] Add tests for nested generic functions (#20631)
  [`cli`] Add conflict between `--add-noqa` and `--diff` options (#20642)
  [ty] Ensure first-party search paths always appear in a sensible order (#20629)
  [ty] Use `typing.Self` for the first parameter of instance methods (#20517)
  [ty] Remove unnecessary `parsed_module()` calls (#20630)
  Remove `TextEmitter` (#20595)
  [ty] Use fully qualified names to distinguish ambiguous protocols in diagnostics (#20627)
  [ty] Ecosystem analyzer: relax timeout thresholds (#20626)
  [ty] Apply type mappings to functions eagerly (#20596)
  [ty] Improve disambiguation of class names in diagnostics (#20603)
  Add the *The Basics* title back to CONTRIBUTING.md (#20624)
  [`playground`] Fix quick fixes for empty ranges in playground (#20599)
  Update dependency ruff to v0.13.2 (#20622)
  [`ruff`] Fix minor typos in doc comments (#20623)
  Update dependency PyYAML to v6.0.3 (#20621)
  Update cargo-bins/cargo-binstall action to v1.15.6 (#20620)
  Fixed documentation for try_consider_else (#20587)
  [ty] Use `Top` materializations for `TypeIs` special form (#20591)
  [ty] Simplify `Any | (Any & T)` to `Any` (#20593)
  ...