#3617 [TUI] include calibration helper in Terminal installer payload

Description

## Problem and result
The installer payload produced by add_installer omits tools/calibrate.py. This is the missing helper reported for saved tuning in #3613. Adding it to INSTALLER_TOOLS makes the existing staging code copy it and record it in the manifest.

The reproduced failure here is the offline staging omission, not the full launch failure.

## Related discussion
Related #3613. This is a focused packaging fix, not a change to calibration behavior.

## Approach
Add calibrate to the existing installer tool entry points and use the existing static local-import closure. The regression calls the real add_installer file-copy path into a temporary directory, then checks that the helper exists, matches the source bytes, and is listed in the manifest. No setup, calibration, engine or serving code is executed by this regression.

## Validation
Linux x86_64, Python 3.12.14; base 011c9e600a93bbc9fd451c563501b5831c32bbca plus this patch (submitted head a0ed21bee97a43f7f645c0fb43402ba626d35bb7). AI-assisted implementation and review; results were checked against actual command output.

**Passed:**
- python tests/terminal/test_installer_payload.py: 1 test.
- python tests/terminal/test_packaging_pins.py: 8 tests.
- python tests/terminal/test_terminal_commit.py: 7 tests.
- git diff --check.
- Independent review: PYTHONDONTWRITEBYTECODE=1 python -m unittest discover -s tests/terminal -p test_installer_payload.py -v: 1 test.
- Independent before/after staging comparison: 33 to 34 files, with tools/calibrate.py the only addition and all 33 existing files unchanged; the tools closure grows from 14 to 15 files.

**Failed:**
- Expected baseline failure: the new regression on unmodified 011c9e6 fails because tools/calibrate.py is absent. The same regression passes with the patch.

**Not run:**
- pytest was not available in the environment; the unittest-compatible test files above were run directly instead.
- Full tests/terminal suite, complete archive build and launch smoke, saved-tuning execution, setup/calibration execution, and hardware/platform validation were not run.

## Limits
This validates and fixes the installer staging omission only. It does not establish the complete dynamic dependency closure, reproduce the reporter's full runtime failure, or qualify a platform. Other potentially missing helpers mentioned in #3613 are outside this change.