* feat(cost): add manual identified Codex token subtotals

Add an opt-in local/SSH token-only view using the official 0.75.0 contract, with bounded decoding and an independent manual process lifecycle. Preserve useful source-failure subtotals without exposing request identities.

Documentation: update usage, cost contracts, requirements, ownership, translations, synthetic screenshot and Unreleased notes; remove the completed TODO item. Verified with make check, package and synthetic Plasma smoke; local Qt/managed-dialog skips and partial QML type metadata require strict CI coverage.

* fix(cost): bound identified subprocess groups

Keep an independent GNU timeout supervisor alive after Plasma retires its source. Terminate the CLI process group at 110 seconds with a five-second kill grace before the 120-second frontend deadline; refuse an unbounded fallback when timeout is unavailable.

Verify stubborn CLI and child termination after timeout, context changes and destruction, plus quoted executable paths and recovery. Documentation: update optional requirements, usage and ownership guides, translations and Unreleased notes. The complete make check, package and synthetic Plasma SSH-failure smoke passed locally; existing local coverage skips remain for strict CI. Addresses CodeRabbit discussion_r4286254109.