release: prepare 0.53.0

[justinjoy]

Summary

• release the query snapshot correctness fixes from Soundness violation: query-mode snapshots emit phantom tuples after retraction and duplicate tuples after input changes (IDB-clear gate keyed on total_iterations) #929/fix(columnar): reset stratum frontiers on full snapshot re-eval #930
• release static plan-literal interning from Incremental wirelog_easy_insert returns WIRELOG_ERR_UNKNOWN (255) when program contains a standalone permission_plane projection #932/fix(plan): pre-intern static string literals #933
• release session-owned pending relation names from wirelog_easy_insert/remove store the relation-name pointer by reference; dereferenced at step() — undocumented lifetime contract silently suppresses incremental deltas #931/fix(columnar): retain canonical input relation names #934
• include the corrected and rebaselined CRDT release performance gate from test(perf): rebaseline CRDT gate after correctness fix #935
• set the project version to 0.53.0 and add release/migration notes

Validation

• meson test -C build --print-errorlogs: 250 passed, 0 failed, 10 environment-gated skips
• meson test -C build --suite abi --print-errorlogs: 32/32 passed
• changelog format, version sync, and 0.53.0 changelog extraction passed
• strict CRDT gate on 752a7e3, CPU 0 / performance governor / REQUIRE mode: result 104,851; median 36,705.0 ms; CoV 0.605%; target 38,120 ms; passed
• Implementation Skill Architect, Critic, and Reviewer: APPROVE

Publication checklist

• Full PR CI passes
• Rebase merge and verify the merged tree matches the reviewed tree
• Confirm a GPG signer and create only a signed v0.53.0 tag
• Resolve the absent tag-artifact workflow: explicitly approve a changelog-only release or provide and verify release artifacts
• Publish the GitHub Release with notes extracted verbatim from CHANGELOG.md

This remains a draft until the signing and artifact-publication requirements are resolved.