Fix #640: recognize chained-dot usage of $-aliased attributes

[bibonix]

Fixes #640.

The bug

redundant-object flags self as redundant for the snippet from the issue:

[bts] > bytes-as-input
  [size] > read
    ((input-block bts --).read size).self > @
    [data buffer] > input-block
      buffer > @
      $ > self

The XMIR shows the only reference to self as <o base=".self"/> (a chained method call on the result of (input-block bts --).read size), but the existing usage XPath only matches @base values starting with ξ:

^ξ(?:\.ρ)*\.self(?:\.[\w-]+)*$

So the count of usages stays at 0, the <= 1 condition fires, and the lint emits "The object self is redundant and may be inlined" — but inlining is impossible here, since self aliases $ and (...).$ is not valid EO.

Fix

src/main/resources/org/eolang/lints/misc/redundant-object.xsl: add a second regex matching the chained-dot usage form (^\.<name>(?:\.[\w-]+)*$), and skip the warning when the candidate's @base='ξ' and at least one chained-dot usage exists. Same-level redundant aliases stay flagged because their usages still appear under the ξ.<name> shape, so all existing catches-* packs continue to fire.

Test

New pack allows-self-used-via-chained-dot.yaml reproduces the issue example and asserts zero defects. Without the XSL change it fails with the "self is redundant" warning; with the change it passes. The full LtByXslTest#testsAllLintsByEo parameterized suite (346 packs) is green.