feat(core): use "Initiate connection" bootloader label on T2T1, T3B1, T3T1

[Hannsek]

Summary

• Replaces the outdated INSTALL FIRMWARE / INSTALL FW button label on the bootloader intro screen with a label that accurately describes what tapping it does — initiating the USB connection to the host
• T3W1 (Safe 7) already used Initiate connection; this aligns all other Core devices with that wording
• T3B1 (Safe 3) uses the shortened Init connection to fit the 128×64 px display with the split-button layout

Device	Layout	Old label	New label
T3B1 (Safe 3)	layout_caesar	INSTALL FW	Init connection (auto-uppercased by FONT_NORMAL_UPPER)
T3T1 (Safe 5)	layout_delizia	INSTALL FIRMWARE	INITIATE CONNECTION
T2T1 (Model T)	layout_bolt	INSTALL FIRMWARE	INITIATE CONNECTION

Test plan

• Build bootloader emulator for each model (TREZOR_MODEL=T3T1/T3B1/T2T1 make build_bootloader_emu) and verify the intro screen shows the new label
• Confirm label fits within button bounds on T3B1 (128×64 display)
• Update Crowdin translation strings for all three models

Closes #6824

🤖 Generated with Claude Code

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 1fd8b486-50f1-481f-90f8-bb96e8f2917b

📥 Commits

Reviewing files that changed from the base of the PR and between e56ca5b and aa31507.

📒 Files selected for processing (3)

• core/embed/rust/src/ui/layout_bolt/bootloader/intro.rs
• core/embed/rust/src/ui/layout_caesar/bootloader/intro.rs
• core/embed/rust/src/ui/layout_delizia/bootloader/intro.rs

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Walkthrough

Three bootloader intro screen files are updated to change button labels for clarity. The host button label is changed from "INSTALL FIRMWARE" or "INSTALL FW" to "INITIATE CONNECTION" or "Init connection" across the bolt, caesar, and delizia layout variants. No logic, event handling, or control flow is altered.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: updating bootloader button labels across three device models (T2T1, T3B1, T3T1) to use 'Initiate connection'.
Description check	✅ Passed	The description provides a comprehensive summary with clear rationale, device-specific label mappings, a test plan with checkboxes, and reference to the closed issue.
Linked Issues check	✅ Passed	All code changes in the PR directly meet the acceptance criteria from issue #6824: the bootloader button label is updated to 'Initiate connection' (or 'Init connection' on T3B1) across all three specified device models.
Out of Scope Changes check	✅ Passed	All changes are narrowly scoped to updating button labels in bootloader intro files for three layouts, with no unrelated modifications to logic, event handling, or other systems.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/bootloader-initiate-connection-label

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[github-actions]

en main(all)

model	device_test	click_test	persistence_test
T2T1	test(all) main(all)	test(all) main(all)	test(all) main(all)
T3B1	test(all) main(all)	test(all) main(all)	test(all) main(all)
T3T1	test(all) main(all)	test(all) main(all)	test(all) main(all)
T3W1	test(all) main(all)	test(all) main(all)	test(all) main(all)

Latest CI run: 24883106124

[obrusvit]

Can you provide screenshots?

[TychoVrahe]

TS3 screenshot, looks ok-ish to me but the shortened version makes it a bit weird. Your call, codewise its fine.

[TychoVrahe]

[TychoVrahe]

[TychoVrahe]

One more note @Hannsek - use hannsek/fix/bootloader-initiate-connection-label as branch name next time :)

Also i'll let you judge whether or not this deserves a changelog entry, if not, you can add [no changelog] into the commit message next time to have green CI