Add bash/shell repomap support

[Kcstring]

Summary

Adds tree-sitter query support for Bash/shell scripts so that .sh, .bash, and .zsh files appear in the repo map with their function definitions.

New file: aider/queries/tree-sitter-language-pack/bash-tags.scm

; Bash / shell script function definitions.
; Matches both POSIX-style `name() { ... }` and keyword-style
; `function name() { ... }` / `function name { ... }`.

(function_definition
  name: (word) @name.definition.function) @definition.function

This captures both declaration styles supported by the tree-sitter-bash grammar:

# POSIX-style
greet() { echo "Hello"; }

# Keyword-style
function deploy() { echo "Deploying"; }

Test plan

• Added tests/fixtures/languages/bash/test.sh with representative function definitions
• Added test_language_bash to TestRepoMapAllLanguages — verifies that greet appears in the generated repo map
• python -m pytest tests/basic/test_repomap.py::TestRepoMapAllLanguages::test_language_bash -xvs passes locally

[CLAassistant]

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