IB-WP-0016-T03: scale-aware planning

Replace generate plan's full-prompt dump with a compact summary that
reports selected-chunk counts, selected chapter numbers, per-workflow
call counts, prompt-word and token estimates, and a rough USD cost when
--cost-per-1k is supplied. Selection filters --chapter (label or number,
repeatable), --from-chapter / --to-chapter (numeric range), and --chunk
(repeatable id) shape the estimate. Budget caps --max-calls and
--cost-cap are reported as exceeds_* booleans so callers can fail fast
before run.

The old full per-workflow plan with prompts remains available behind
--full so deep inspection is opt-in instead of the default.

Whole-Lefevre estimate at default max_words=800: 146 chunks, 730 calls,
~518k prompt tokens, ~$155 at $0.30/1k. Chapters 3-5 only: 19 chunks,
95 calls, ~64k tokens. 87 tests pass.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docs/generic-source-generator.md

@@ -48,6 +48,34 @@ infospace-bench generate status ./infospaces/book-space
 shows chunk counts, generated artifact counts, evaluations, metrics, history,
 and stale source/profile inputs.
 
+### Scale-aware plan
+
+`generate plan` returns a compact estimate by default — counts of selected
+chunks, calls per workflow, prompt-word and token estimates, and a rough
+USD cost when `--cost-per-1k` is supplied. Long corpora no longer dump
+hundreds of full prompts unless `--full` is set.
+
+```bash
+infospace-bench generate plan ./infospaces/book-space \
+  --from-chapter 1 --to-chapter 3 \
+  --cost-per-1k 0.30 \
+  --max-calls 50 \
+  --cost-cap 2.00
+```
+
+Selection filters:
+
+- `--chapter LABEL` (repeatable) — match a chapter by roman/arabic label
+  or numeric value (e.g. `--chapter I` or `--chapter 2`)
+- `--from-chapter N` / `--to-chapter N` — numeric chapter range
+- `--chunk ID` (repeatable) — exact source chunk id (e.g.
+  `chapter-01-part-002`)
+
+Budget flags `--max-calls` and `--cost-cap` are reported as
+`exceeds_max_calls` / `exceeds_cost_cap` booleans in the summary, so a
+caller can fail fast before invoking `run`. Use `--full` to opt back into
+the full per-workflow plan with prompts for deep inspection.
+
 ## OpenRouter
 
 Live model calls are explicit: