sdd init skips new gitignore lines unless --force #45

What happened

sdd init on a project that already has .sdd/config.yaml throws before it can add newly required ignore lines.

packages/core/src/init.ts returns at the existing-config check (around lines 82–85) when force is false. ensureIgnoreEntries (around lines 297–313), which now appends role-runs/, runs only after that check.

Repro

1. Use a project that already has .sdd/config.yaml and a .sdd/.gitignore that ends at models/.
2. Install sdd 0.17.2 (main aecf412, role create/run).
3. Run sdd init --here --no-agent with no --force.
4. The command exits with Already initialized (...). Use --force to merge defaults and refresh unchanged generated files.
5. .sdd/.gitignore still has no role-runs/.

sdd init --here --force --no-agent does append role-runs/ and keeps local constitution and workflow edits. That is a heavier hammer than adding one ignore line.

Why this is separate from #36

#36 is about bundled workflows and templates that stay hidden, and about --force still refusing to refresh an edited or unmarked file. This one is the early return: a new required ignore entry is unreachable without --force, even when the ignore file would only gain a line.

Expected

An existing project can pick up new required .sdd/.gitignore entries, including role-runs/, without --force and without rewriting config, memory, or workflows.