refactor(session): fold the session family into packages/session/

git mv the 12 packages from session-persistence/, session-projection/,
session-title/, and telemetry/ into one session/ group per the
regrouping RFC; merge the four group READMEs into one bilingual
triplet; rewrite the group segment in tsconfig references (intra-group
references shorten to ../<pkg>), tsconfig.base.json paths/globs,
knip.json keys, vitest include, gate scripts, and authored doc/note
citations; regenerate module graph, doc graphs, catalogs, and the
lockfile importer keys. No npm names change.

Full unit suite: 8779 passed; the 18 reported failures reproduce as
env flakes (ambient-proxy IPv6 tunneling, watched-dir inotify
timeouts under parallel load) — each passes in isolation with
NO_PROXY set, matching their known pre-existing behavior on master.

scripts/run-gates.ts

@@ -312,7 +312,7 @@ function nodeCompatSmokeGates(options: { cliSmoke?: boolean } = {}): Gate[] {
     pnpmExec('jsonl-zstd-smoke', [
       'vitest',
       'run',
-      'packages/session-persistence/session-persistence-jsonl/tests/zstd.compat.spec.ts',
+      'packages/session/session-persistence-jsonl/tests/zstd.compat.spec.ts',
     ], { label: 'JSONL Zstandard smoke' }),
     pnpmExec('dsh-source-launch-smoke', [
       'vitest',