fix(encoding): backport corruption-safety fixes to release/v5.0 (#8154)

Backport the corruption-safety fixes from:
- #8138: #8138
- #8144: #8144

The v5.0 stable line still reaches the vulnerable VariableFullZip
length-prefix parser and unchecked variable-width offset paths through
the default reader.

Release-specific adaptation: use the v5.0 error-construction and
synchronous reader APIs; retain one native truncated-prefix regression
plus native V2.1/V2.2/V2.3 reader coverage, without main-only
async/lazy/RLE scaffolding.

Validation:
- cargo fmt --all: passed
- Targeted lance-encoding/lance-file corruption regression tests: passed
(1 + 12 + 1 + 1 + 5 + 6 tests)
- cargo clippy --all --tests --benches -- -D warnings: passed
- Rust build-no-lock, MSRV, clippy, and format checks: passed;
linux-build remains the known ethnum/current-nightly E0512 tooling
baseline.
- No manifests, lockfiles, Python extras, or workflows were changed on
this branch.
- Python and cargo-deny failures are baseline exceptions; the standalone
create-rc workflow has no needs on these validation workflows, so no
release artifact blocker was identified.
- This branch retains the existing recovery history around the #8144
backport (duplicate application followed by revert); no history was
rewritten, and the final tree contains the intended fix.
- Keep nightly/dependency maintenance separate from this focused
backport.

---------

Co-authored-by: m00dy <professor.moody@pm.me>

Author: Xuanwo