T08: give provisional defaults an owner, a date, and a visible age

Five scenarios encoded U-item defaults with no owner and no review date,
so they could shape the kernel indefinitely while looking handled.

Each now carries provisional_owner and provisional_raised, and the
runtime's ScenarioFile learned both fields (deny_unknown_fields meant
adding them to YAML alone would have failed every scenario -- the parser
had to agree).

make coverage reports every provisional item with its owner and age in
days, warns on any with no owner, and warns past 30 days. It WARNS
rather than breaking the build, on purpose: the ruling is ground-game's
to make and the kernel cannot make it for them. What the loop can
enforce is that evidence files list them, which is now stated in
GroundRules.

rule-coverage --self-test gained an assertion that every provisional
item has both fields, so the next one added without them fails a
command rather than passing quietly.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

specs/GroundRules.md

@@ -210,6 +210,15 @@ terms.
 
 ## Underdetermined in dataset 0.1 — PROVISIONAL defaults (flag to ground-game)
 
+**Owner: ground-game. Raised: 2026-07-31.** Every U-item carries an owner
+and a raise date so its age is visible; `make coverage` reports both and
+warns past 30 days. CI **warns rather than breaks** — the ruling belongs
+to ground-game and the kernel cannot make it for them — but every evidence
+file that depends on one must list it (CB-WP-0003 T08).
+
+A ruling flips the *scenario*, not the kernel: the default is encoded in a
+scenario tagged `provisional: true`, so a correction is a data change.
+
 Formalization exposed points the dataset does not decide. Simulation uses
 the stated default; each is tagged in scenarios that depend on it and must
 be confirmed or corrected by ground-game.