feat: summarize-all batch (consolidation step 1)

Harden summarize_session to chunk + merge long sessions (imported convos can
exceed the local model's context), and add summarize_all: idempotent, resumable
batch that summarizes every session needing it (skips up-to-date ones), with
progress logged to the live log. `lyra-summarize [limit]` CLI.

This is the first consolidation stage feeding the profile (semantic memory) and
era-rollup tiers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

pyproject.toml

@@ -17,6 +17,7 @@ dependencies = [
 lyra = "lyra.__main__:main"
 lyra-web = "lyra.web.server:serve"
 lyra-import = "lyra.ingest:main"
+lyra-summarize = "lyra.summary:main"
 
 [dependency-groups]
 dev = [