fix(rust): Flush stdout after print to fix stream mode display

[cfsmp3]

Summary

• Fixes empty [Stream mode: ] display when using --input <format> options
• Adds explicit stdout/stderr flush after print operations in Rust logger

Problem

When using --input scc (or other formats), the startup output showed:

[Stream mode: ]

Instead of:

[Stream mode: SCC]

Root Cause

The Rust logger's print() function uses print!() which doesn't automatically flush stdout. When mixing C and Rust code that both write to stdout, the Rust output was getting buffered and not appearing before the C code continued writing.

Solution

Added explicit std::io::stdout().flush() after each print!() call to ensure output appears immediately and interleaves correctly with C code.

Test plan

• --input scc shows [Stream mode: SCC]
• --input mkv shows [Stream mode: MKV]
• --input ts shows [Stream mode: Transport]
• Autodetect shows [Stream mode: Autodetect]
• All 265 Rust tests pass

🤖 Generated with Claude Code

[ccextractor-bot]

CCExtractor CI platform finished running the test files on linux. Below is a summary of the test results, when compared to test for commit 8aadbfb...:

Report Name	Tests Passed
Broken	13/13
CEA-708	14/14
DVB	6/7
DVD	3/3
DVR-MS	2/2
General	27/27
Hardsubx	1/1
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	86/86
Teletext	21/21
WTV	13/13
XDS	34/34

NOTE: The following tests have been failing on the master branch as well as the PR:

• ccextractor --autoprogram --out=srt --latin1 --quant 0 85271be4d2..., Last passed:

  Test 7596

This PR does not introduce any new test failures. However, some tests are failing on both master and this PR (see above).

Check the result page for more info.

[ccextractor-bot]

CCExtractor CI platform finished running the test files on windows. Below is a summary of the test results, when compared to test for commit 8aadbfb...:

Report Name	Tests Passed
Broken	13/13
CEA-708	14/14
DVB	7/7
DVD	3/3
DVR-MS	2/2
General	27/27
Hardsubx	1/1
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	86/86
Teletext	21/21
WTV	13/13
XDS	34/34

All tests passed completely.

Check the result page for more info.