feat(simulation): the demo's gate is anchored to real cost lines (P4 pkt. 0)

The validator can reconcile a proposal against the project's actual cost lines
(S4.0 stage 0), but only when the knowledge base ships a cost-baseline.json —
and no bundle under shared/ has one. So on stage the gate reasoned only about
numbers the proposal supplied itself.

The reserve can never receive the file in shared/ (pull-only subtree, and demo
criterion 8 requires the goldens byte-unchanged). That is a placement
constraint, not an impossibility: materialize_anchored_bundle copies the bundle
and adds the file outside shared/, and the run path reads it through exactly
the seam a delivered bundle would use.

The baseline is DERIVED IN CODE from the scripted register, never typed beside
it — two sources of the same numbers drift, and drift is precisely what the
10 % probe models. On GO day the direction reverses (plan P3 b). Both scripted
replies must state the same cost lines or ValueError: were they to differ,
hypothesis #1 would be falsified by stage 0 instead of by P90 — the same
REJECTED line on screen, a different mechanism behind it.

10 % probe, measured: baseline x 1.10 -> FORKASTET at stage 0, before the
solver; corrected -> FORESLÅTT. Criterion 6 re-measured (stdout byte-identical
across two runs); stderr unchanged at 6 lines. The ONLY diff against the
un-anchored demo is the new KUNNSKAPSBASE block — everything else is
byte-identical, which is the problem: an anchoring nobody can see is one nobody
can check. Hence it is printed, and hence `provenance` is a required argument.
769 -> 775 passed.

Five mutations red + green control. The measurement failed the TEST first:
"ingen kostbaseline erklært" CONTAINS "kostbaseline erklært", and
ENERGI-TOTAL-EL already appears in the Step-2 line, so both assertions survived
the detach mutation. The two branches now share no wording.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GD6Y2Y23NZZxPYtSRoCmst

README.md

@@ -66,6 +66,13 @@ reviewer would days later — is merged from disk into the next run's store befo
 formed (write file → merge → fold). Both markers are present in Run B's prompt and absent from
 Run A's. Nothing crosses in memory.
 
+The run is **anchored**: the demo copies the example knowledge base and adds a `cost-baseline.json`
+— the project's actual cost lines — so the validator's first stage reconciles every cost line a
+proposal claims against them, before the solver runs. The declared baseline is printed at the top,
+because it is the one property the rest of the output looks identical with or without. Those
+numbers are synthetic, derived from the scripted replies themselves; a knowledge base that ships
+its own baseline replaces them through the same seam, with no code change.
+
 **3 — Run the loop over a knowledge base, with answers you supply.** Write the stand-in replies,
 then point the CLI at the bundle: