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.

packages/examples/acp-demo/tests/built-bin.e2e.ts

@@ -34,8 +34,8 @@ const dshPackages = [
   'examples/agent-spine-demo', 'core/agent', 'core/session', 'core/system-prompt',
   'core/tools', 'core/agent-loop', 'llm/llm', 'bash/bash',
   'bash/bash-local', 'bash/tool-bash', 'subprocess/subprocess', 'subprocess/subprocess-local', 'context/workspace-context', 'support/invariants', 'ui/app-boot',
-  'session-persistence/session-persistence',
-  'session-persistence/session-checkpoint-policy', 'session-persistence/session-persistence-jsonl',
+  'session/session-persistence',
+  'session/session-checkpoint-policy', 'session/session-persistence-jsonl',
   'acp/acp', 'examples/acp-demo', 'util/paths',
 ]
 const vendorPackages = [

packages/examples/acp-demo/tsconfig.json

@@ -39,10 +39,10 @@
       "path": "../../context/workspace-context"
     },
     {
-      "path": "../../session-persistence/session-checkpoint-policy"
+      "path": "../../session/session-checkpoint-policy"
     },
     {
-      "path": "../../session-persistence/session-persistence-jsonl"
+      "path": "../../session/session-persistence-jsonl"
     },
     {
       "path": "../../support/invariants"

packages/examples/agent-spine-demo/tsconfig.json

@@ -27,7 +27,7 @@
       "path": "../../core/session"
     },
     {
-      "path": "../../session-title/session-title"
+      "path": "../../session/session-title"
     },
     {
       "path": "../../core/system-prompt"