[Performance] Allocate AlignedTVList primitive arrays lazily

[jt2594838]

Description

Follow-up to #18264. This PR contains only the lazy primitive-array allocation changes on top of the merged dynamic-bitmap implementation.

• Keep null placeholders for newly added or unwritten aligned columns and allocate each PrimitiveArray only on its first actual write.
• Update TsFileProcessor memory accounting for lazy primitive-array allocation.
• Cover clone/read/WAL/null-tablet paths with unit tests.
• Add a 256 MiB integration test that writes 40,000 rows to one aligned measurement and then one row to 1,200 new measurements, preventing the eager-allocation memory failure.
• Add a real 1C1D integration performance comparison against a master worktree, including both sparse/lazy-column and fully non-null aligned-tablet workloads, and generate a Markdown report.

Performance

Compared master 91476b0df7 with candidate b7f846ec98:

Workload	master	candidate	Result
Sparse/lazy columns	30.598 ms	14.294 ms	latency -53.29%, throughput +114.07%
Fully non-null aligned tablets	123.767 ms	123.359 ms	+0.33%

Tests

• AlignedTVList unit tests: 14/14 passed.
• 256 MiB low-memory integration test passed (40,000 historical rows, then one row across 1,200 new columns).
• 1C1D worktree comparison completed for master and candidate, including the no-null workload.

[HTHou]

calculateRamSize() still multiplies the number of timestamp blocks by alignedTvListArrayMemCost(), which assumes that every column has a materialized primitive array in every block. That assumption is no longer valid after this change.

[HTHou]

This still charges the dense per-block cost for every existing column whenever a new block is acquired, while AlignedTVList.expandValues() now only adds null placeholders and allocates primitive arrays on their first actual write.