Feat ja translation skill

[HARDIK-WEB-OSS]

Description

closes: #61997
related: #61984

Defined translation agent skills for the Japanese (ja) locale according to #62059.

• Terminology: Cross-linked translation.json for Katakana consistency (e.g., タスク for Task, トリガー for Triggerer).
• Noise Reduction: Removed i18n policy links per feedback in add SKILL.md and zh-CN agent skill instruction #62059 to narrow the agent context window.
• Token Efficiency: Using short SPDX license header to reduce overhead as proposed in Allow to use short SPDX licence identifier for selected files #62073.
• Linguistic Rules: Instructed agent to use polite 'Desu/Masu' form and noted that Japanese does not use plural suffixes.

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)
  Generated-by: [Gemini] following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[HARDIK-WEB-OSS]

Hi @shahar1 and @Dev-iL, I have reverted the unrelated BigQuery changes as suggested. I have also updated the license header to include the URL per the feedback. My branch is now clean and only contains the Japanese locale translation agent skill. Ready for another look!

[Dev-iL]

I have also updated the license header to include the URL per the feedback.

I still don't see it.

[HARDIK-WEB-OSS]

Hi @Dev-iL and @shahar1, I've fixed the license header to the minimal 3-line format as per the feedback. I've also squashed the commits and cleaned the branch history. Re-opened and ready for a final review.

[jason810496]

For all Japanese translation owners, I’d appreciate it if you could take a look when you have a moment. Thank you!

cc @uranusjr @sekikn @rsanda

[HARDIK-WEB-OSS]

Hi @shahar1, I have resolved all conversations and Dev-iL has approved the changes. The PR is now clean, squashed, and up-to-date. Could you please trigger the workflows and provide the final review? Thanks!

[rsanda]

Sorry for the delay and thanks for working on this.
The rules that are mentioned are correct, some missing ones that I set when translating:

Core Rules

• Put a space before and after English words, numerical values, and half-width caracters if it is not at the beggining or end of the sentence.
• Use the polite version of "desu/masu" when a user action is expected.

Terminology Guidelines

• Keep "Providers" as there is no good translation
• "Trigger" as "トリガー" but "Triggerer" is left as "Triggerer" since "トリガーラー" is not common and difficult to understand

[HARDIK-WEB-OSS]

Thank you for the detailed feedback @rsanda ! I've updated the ja.md file to include:

• The specific spacing rules for English words/numbers.
• Updated terminology (Providers, Trigger, and Triggerer) exactly as you mentioned.
• Re-emphasized the 'Desu/Masu' rule for user actions.

The PR is now updated and ready for final review.