Tokens as a unit people can feel: files, runs, issues and pulls carry a token count the way storage carries MB and GB #403

Owner's intent (2026-10-02): help people build an intuition for context length the way everyone now has one for storage size. Not annoying — informative, in the quiet places sizes already live.

Acceptance:

• [ ] one formatter for token counts (e.g. 1.2k, 48k, 1.1M tok) used everywhere, with a tooltip saying which tokenizer and that it is an estimate where it is one
• [ ] a file in the browser and the editor shows its token count beside its byte size; a directory listing shows per-file counts and a total
• [ ] a run shows tokens in, tokens out and the context high-water mark beside its cost; an issue and a pull show the total tokens the work on them consumed
• [ ] the Subscriptions page and the board state windows in tokens as well as percentages, so the two intuitions meet
• [ ] docs/DESIGN.md gets the rule: a token count is shown where a byte size is shown, never as a badge on its own

Files: a small src/kernel/tokens-format.ts (estimate via a fast tokenizer or a calibrated bytes-per-token ratio per language), src/web/pages/browse.ts, pages/runs.ts, studio/change.ts, pages/settings.ts (Subscriptions), docs/DESIGN.md. Depends on the usage ledger in #341 for run and issue totals; the file counts can land first. Scout fits the first slice.

Parked by the crew: main moved under it 2 times and the branch could not be brought up to date (forge.json) (pull #526 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.