The surfacing half of the per-agent favorite-tools stat. Reads a
`bash_commands(ts INTEGER NOT NULL, head TEXT NOT NULL)` table from the
per-agent turn-stats.sqlite — one row per bash task, written by
hive-bash-mcp (the capture half, landing separately) — and rolls up the
top-10 command heads for a doughnut, mirroring the existing
tool_breakdown.
- stats.rs: new `Snapshot.bash_breakdown` + `read_bash_breakdown()`.
The read is guarded: a missing `bash_commands` table (capture hasn't
shipped / agent hasn't run a bash task) maps to an empty list, never
an error — the snapshot degrades gracefully. Unit tests cover both
the absent-table and populated cases (incl. window cutoff + ordering).
- frontend: a "favorite tools (bash)" doughnut card on the agent /stats
page, kept hidden until bash_breakdown has data so it never shows a
permanently-empty doughnut while capture is pending.
Part of #1433 (does not close it — pairs with the hive-bash-mcp capture
half). Inert until the capture lands; merge order with it is irrelevant.
a5914274ba