Explicit PRODID handling

[rfc2822]

Refactoring: move PRODID to where it belongs

[Copilot]

Pull Request Overview

This PR introduces explicit handling of the PRODID property in both vCard and iCalendar generation, replacing reliance on static or default PRODID values with explicit parameters.

• Explicit PRODID is now passed as a parameter to various write methods.
• Build configuration and test cases were updated to reflect the new product/project naming and PRODID propagation.

Reviewed Changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
settings.gradle.kts	Updated the root and library project names to reflect the proper project naming.
lib/src/main/kotlin/at/bitfire/vcard4android/ContactWriter.kt	Modified the vCard writer to accept an explicit productId and apply it when setting the PRODID property.
lib/src/main/kotlin/at/bitfire/vcard4android/Contact.kt	Updated vCard write methods to require a productId parameter rather than relying on a static variable.
lib/src/main/kotlin/at/bitfire/ical4android/Task.kt	Changed the write() function to require a prodId parameter and updated how PRODID is added to the calendar.
lib/src/main/kotlin/at/bitfire/ical4android/JtxICalObject.kt	Propagated the explicit prodId parameter in calendar conversion and output methods.
lib/src/main/kotlin/at/bitfire/ical4android/JtxCollection.kt	Updated ICS collection generation to require and use an explicit prodId.
lib/src/main/kotlin/at/bitfire/ical4android/ICalendar.kt	Modified the PRODID extension to properly append user agent information to the passed PRODID.
lib/src/main/kotlin/at/bitfire/ical4android/Event.kt	Updated event write() methods to include an explicit prodId for PRODID generation.
Test Files	Adjusted all test cases to pass the new explicit product/prod IDs to the write methods.

Comments suppressed due to low confidence (4)

settings.gradle.kts:23

• Ensure the new root project name 'synctools' is consistent with your repository and organizational naming conventions.

rootProject.name = "synctools"

lib/src/main/kotlin/at/bitfire/vcard4android/ContactWriter.kt:78

• Confirm that the string formatting for PRODID meets the requirements of your clients and downstream consumers; consider validating the resulting format against the vCard specification.

        vCard.productId = ProductId("$productId (ez-vcard/${Ezvcard.VERSION})")

lib/src/main/kotlin/at/bitfire/vcard4android/Contact.kt:128

• [nitpick] Consider aligning the PRODID handling between the vCard API (which uses a String) and the iCalendar API (which uses a ProdId type) for consistency in your codebase.

    fun writeJCard(os: OutputStream, productId: String) {

lib/src/androidTest/kotlin/at/bitfire/ical4android/JtxCollectionTest.kt:154

• Remove the debug print statement before merging to maintain clean test output.

        System.err.println(ics)