feat(analyse): add Bash language support

[ubmarco]

Adds bash as a supported comment_type for marker extraction. Closes #48.

What

• New CommentType.bash, discovering .sh, .bash, .zsh and .ksh files.
• Bash has only # line comments, so extraction reuses the existing hash-comment path: a (comment) @comment tree-sitter query over the tree-sitter-bash grammar, with function_definition scope nodes.
• Adds the tree-sitter-bash>=0.25.1 dependency.

Tests & docs

• A default_oneliner_bash case in the shared oneline.yaml extraction fixture, with its captured snapshot.
• Discovery coverage for the new extensions; the comment-type enum error-message tests updated.
• Documented as a new FE_BASH feature, with the configuration / analyse / changelog pages updated.

Not included

Fish shell — it is not POSIX-compatible and no tree-sitter-fish grammar is published on PyPI, so it cannot be wired into this package. Can be revisited if a PyPI grammar becomes available.

[ubmarco]

Review

Must fix — the supported-styles table in configuration.rst is corrupted. The new Bash row was inserted mid-cell into the JSONC row: the continuation line (e.g. the mode line // -*- mode: jsonc -*-) now renders inside the Bash row's "discovered file types" cell, and the JSONC cell loses its example. Move the Bash row below that line. The RST stays syntactically valid, so the docs build can't catch this — worth an eyeball of the rendered table.

Test coverage

• features.rst:255 guarantees that shebang lines never produce spurious markers, but nothing asserts it. Cheapest cover: a second bash case in the declarative oneline.yaml fixture whose source starts with #!/bin/bash. The function name { } definition form is likewise unexercised (the fixture uses greet() { … }).
• FE_BASH lists "association of comments with function definitions" as a key capability, backed by SCOPE_NODE_TYPES:48; the fixture executes that path but nothing asserts the resulting scope.

Otherwise clean. Wiring is complete and consistent: enum + file-type map, query + init_tree_sitter branch, both hard-coded comment_type error-message tests updated, discovery test covers all four extensions, docs and changelog updated. The change is additive — the only user-visible behavior change besides the feature is the schema-validation error string now listing bash. CI is green across the matrix; no earlier review comments to address.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 95.45455% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 91.46%. Comparing base (43927d0) to head (fe82065).

Files with missing lines	Patch %	Lines
src/sphinx_codelinks/analyse/utils.py	80.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #92      +/-   ##
==========================================
+ Coverage   91.40%   91.46%   +0.06%     
==========================================
  Files          34       34              
  Lines        3012     3034      +22     
  Branches      322      323       +1     
==========================================
+ Hits         2753     2775      +22     
  Misses        160      160              
  Partials       99       99              

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[ubmarco]

Review findings addressed in f604413 and fe82065:

1. Table fixed (f604413) — the JSONC example continuation line is back in the JSONC row's cell, and the Bash row now follows it cleanly: configuration.rst:325-332.
2. Shebang and function keyword form covered (fe82065) — new declarative case shebang_oneliner_bash with its captured snapshot: the shebang comment yields no marker and no warning, the need anchors to line 2, and function greet { echo hi; } parses.
3. Scope association asserted (fe82065) — new test_find_associated_scope_bash following the existing per-language pattern: comments associate with the function_definition for both definition syntaxes, plus the enclosing-scope fallback for a comment inside a function body.

Verified with the full tox suite (267 passed, 34 snapshots), mypy, and the pinned pre-commit hooks on the changed files; CI is green on fe82065.