Support non-prefix matching for task-name completion

[DCjanus]

I use fish and would like to complete task names without typing their shared prefixes.

Example mise.toml:

[tasks."backend:compile"]
run = "true"

[tasks."backend:test"]
run = "true"

[tasks."frontend:build"]
run = "true"

Input:    mise run com<Tab>
Expected: backend:compile
Actual:   pyproject.toml  # Falls back to filename completion

Typing mise run backend:com<Tab> correctly completes to backend:compile.

Would you consider supporting non-prefix matching for task names? Separately, should task-name completion avoid falling back to unrelated filenames?

Reproduced with mise 2026.11.3 and fish 4.9.3 on macOS arm64, in a fresh directory with fish user configuration disabled.

AI-assisted — Tool: Codex; model: OpenAI/GPT 6.1 Sol; version: codex-cli 0.168.0-alpha.7.