fix!: activate hooks only in initialized repositories

[badrus123]

Hooks fired in any repository with a detected language, so a repository that never ran forgeguard init was gated, blocked, and written to. That contradicted docs/ARCHITECTURE.md, which states global hooks pass silently outside initialized repositories.

Changes

• Init-only activation. is_hook_project now requires .forgeguard/config.toml; a detected language is no longer treated as consent. evaluate_stop_hook uses the guard too — it previously had none. Nested repositories inside an initialized workspace still inherit gating.
• Retry budget. Retry and no-progress counters both reset when the worktree or task state advances. A session that progressed on every turn could previously exhaust the budget and receive continue: false.
• Duplicate hook registrations. A stop decision is replayed for 1.5s when repository and task state are unchanged, so a global and a project hook entry firing the same event consume one turn of budget, not two.
• Auto-poke recovery. A blocked task releases its auto-poke budget when the session registers a different objective. Reframing the same objective still carries the budget over.
• Command scope. Gates skip the configured commands when every changed path is documentation or an asset. Removed paths and files under test/, tests/, spec/, fixtures/, testdata/ still run them.
• Timeouts. forgeguard init writes a stop-hook timeout covering the configured command budget and repairs existing entries whose timeout is too short.

Verification

cargo test --locked --workspace              107 passed, 0 failed
cargo clippy ... -D warnings                 no issues
cargo fmt --all -- --check                   clean
forgeguard gate --output compact             0 errors, 0 warnings, 0 failed checks
forgeguard doctor                            healthy

Manual reproduction in a scratch repository:

scenario	result
uninitialized repo, stop and context hooks	no output, no .forgeguard/, .gitignore untouched
after forgeguard init, source change	decision: block
after forgeguard init, markdown-only change	pass
deleted source file plus markdown edit	decision: block
two hook registrations, same event	identical decision, one attempt consumed
five turns with real progress	attempt 1/3 each turn, no stop
four turns without progress	escalates to stop on turn three
stop timeout vs command budget	720s >= 600s

Breaking change

Repositories without .forgeguard/config.toml are no longer gated. Run forgeguard init to keep enforcement.