forge: always --effort max + multi-chapter batch (cap 20)

forge.rs threads Effort::Max on gen + cleanup. Audit + summarize stay
default — they're structured-output / tool-shaped tasks where extended
thinking doesn't help. Bumps subprocess timeout from 600s to 1800s so
max-effort prose-craft has the wall clock it needs.

continue_story::run takes a chapter_count param; loops gen+cleanup per
chapter with each iteration's just-written prose appended to context.
Audit fires once at end against the combined batch vs parent canon.
Cap is 20 (~5h wall clock, ~$600 at max effort — beyond that is
operationally absurd).

CLI: 'skald continue --chapters N'. Web: numeric field on both new-
story and continue forms, 1..=20, defaults to 1.

Vendored clawdforge SDK refreshed for the Effort enum.

vendor/clawdforge/src/lib.rs

@@ -53,6 +53,6 @@ pub use client::{Client, ClientBuilder};
 pub use error::Error;
 pub use session::{Session, SessionList, SessionOptions, SessionState, TurnEvent, TurnResult};
 pub use types::{
-    AppToken, AppTokenInfo, FileToken, Healthz, RunFailure, RunRequest, RunResult,
+    AppToken, AppTokenInfo, Effort, FileToken, Healthz, RunFailure, RunRequest, RunResult,
     SystemMode, TokenCreateRequest, TokenList,
 };