docs(demo): nest evidence scorer in demo profiles

Show type evidence wrapping a heuristic base with the RFC example factors, matching the ranking YAML the stack now wires.

Author: behinddwalls

doc/howto/QUICKSTART.md

@@ -74,17 +74,20 @@ Every change writes all of its files into one folder under `demo/`, and `FOLDERS
 
 Set it deliberately when you want a run to show one thing. `FOLDERS=1` puts every change in the same place, so the queue serializes the lot and each change speculates on the one before it. A number well above `COUNT` keeps them all apart, so they go out together.
 
-How much speculation that turns into is capped by the queue's **build budget** — how many builds it may have occupying CI at once, counted across every in-flight batch rather than per batch. It defaults to 4 and is set per queue in the provider's `profiles.yaml`. The demo also sets **predictor factors** there so speculation ranking revises the scorer's price when a path passes or fails or a batch is merging or cancelling; omitting that block leaves every factor at `1`, which is a no-op and ranks on the scorer alone.
+How much speculation that turns into is capped by the queue's **build budget** — how many builds it may have occupying CI at once, counted across every in-flight batch rather than per batch. It defaults to 4 and is set per queue in the provider's `profiles.yaml`. The demo also sets **evidence scorer factors** there so speculation ranking revises the base price when a path passes or fails or a batch is merging or cancelling; omitting `factors` leaves every factor at `1`, which is a no-op and ranks on the nested base alone.
 
 ```yaml
 defaults:
   speculator: {buildBudget: 4}
-  predictor:
+  scorer:
+    type: evidence
     factors:
       pathPassed: 10
       pathFailed: 0.3
       merging: 12
       cancelling: 0.1
+    base:
+      type: heuristic
 
 queues:
   - name: demo-queue

service/submitqueue/demo/provider/fake/profiles.yaml

@@ -23,14 +23,17 @@ defaults:
   # of the outcomes it is waiting on. Four is the built-in default.
   speculator: {buildBudget: 4}
   # Example evidence factors from the outcome-predictor RFC. Omitted keys would
-  # stay at 1 and ranking would stay on the scorer alone; writing them out makes
+  # stay at 1 and ranking would stay on the base price; writing them out makes
   # the demo show how path results and batch state revise that price.
-  predictor:
+  scorer:
+    type: evidence
     factors:
       pathPassed: 10
       pathFailed: 0.3
       merging: 12
       cancelling: 0.1
+    base:
+      type: heuristic
 
 queues:
   # The queue `make demo-requests` and `make land` use by default.

service/submitqueue/demo/provider/git/profiles.yaml

@@ -14,12 +14,15 @@ defaults:
   analyzer: {type: all}
   # Same example factors as ../fake/profiles.yaml — see that file for why they
   # are written out rather than left at the neutral default of 1.
-  predictor:
+  scorer:
+    type: evidence
     factors:
       pathPassed: 10
       pathFailed: 0.3
       merging: 12
       cancelling: 0.1
+    base:
+      type: heuristic
 
 queues:
   # The queue `make demo-requests` and `make land` use by default. Serializes

service/submitqueue/demo/provider/github/profiles.yaml

@@ -12,12 +12,15 @@ defaults:
   analyzer: {type: all}
   # Same example factors as ../fake/profiles.yaml — see that file for why they
   # are written out rather than left at the neutral default of 1.
-  predictor:
+  scorer:
+    type: evidence
     factors:
       pathPassed: 10
       pathFailed: 0.3
       merging: 12
       cancelling: 0.1
+    base:
+      type: heuristic
 
 queues:
   - name: demo-queue