fix(newos4): one error counter for errors/dashboard/world-model (v4.6.61)

Packet 2 (three surfaces, three answers). Measured first: `errors` scanned
/logs/current.log for [ERROR] lines, but that file only ever receives explicit
terminal.log('ERROR', ...) calls -- exactly one call site in the whole app -- so it
read 0. The dashboard added DebugSupervisor._errorDB plus failed tool calls (18),
and the world model read the debug DB alone (11).

- terminal.countErrors() / countLogErrors(): the single counter, exposed on the one
  object all three surfaces already hold
- `errors` prints the canonical total with its breakdown, the entry list (hash,
  count, severity, message), and reports the log scan separately as a mirror
- dashboard health.errors and health.errorBreakdown derive from it
- world model telemetry.recentErrors derives from it, plus errorsBySource
- terminal.log('ERROR', ...) now also records into DebugSupervisor, so the log is a
  human-readable mirror of one store instead of a second store almost nobody wrote

Verified live on v4.6.61: with a seeded debug entry + failed tool call, all three
report 2; a single log('ERROR') call moves debug 1->2 and the total by exactly 1
(the mirror line is counted once, in the log, and reported separately).

0 files changed, 0 insertions, 0 deletions