fix(pm): bare-root-worklist sweeps the bare ROOTS / DIRS spellings (#15767)

POPULATION_CONSTANT required a literal underscore in every alternative but
POPULATION, so `SCAN_ROOTS` matched and the plainest spelling of the shape
this sweep exists to find -- `const ROOTS = [...]` -- did not. The
instrument that reports on invisibility was itself blind to it, and no
reader of its output could infer the omission from the output.

Admitted as two EXACT alternatives, never as `_?` on the two that were
there: that looser edit also admits ROOT, DIR and SCANROOTS, and the bare
singular ROOT is this tree's commonest name for a repo root -- one path
fragment, the thing the regex exists to exclude. Pinned in --self-test in
both directions, with SCAN_ROOTS / SCAN_DIRS / POPULATION as the control
that the widening added alternatives rather than replacing them.

Measured on 66e68ad before the regex moved: the two names add 23 rows
across 11 gate source files, and the profile is the OPPOSITE of --wide --
21 of 23 are real populations (recursive readdirSync walk, or git ls-files
over the root), 2 are a label/name field beside a separator-carrying path
that was always visible, and NONE is a join() path component in a gate that
never reads the root. 12 land REACHABLE against declarations their gates
already carry; 11 land open with no verdict.

No verdict rows are written -- the map is shrink-only and maintainer-ruled.
The 11 go into a new UNJUDGED bucket: seen, measured, judged by nobody, and
printed under the worklist so the debt list stops reading as complete. The
exclusion buys no silence, because --self-test holds the bucket SET-EQUAL to
the open rows carrying no verdict in both directions -- a row can only leave
the FRESH case by being NAMED, and anything unlisted still prints as
UNTRIAGED and still reds.

The two battery floors this touches are re-baselined to their measured run
counts (17 and 19 static cases, no loops or conditionals in either region),
the convention the roster's other entries follow.


Claude-Session: https://claude.ai/code/session_012zGPuVVX3deAx9LdjK8jCk

Co-authored-by: Claude <noreply@anthropic.com>

Author: claude[bot]