chore(release): bump chart to 1.9.7

[LukasWodka]

Declares the next release so the train can create pre-release v1.9.7-rc.N on the staging hop — the first FR-able artifact for the Windows installer sweep (#437–#447, #377) — and stable v1.9.7 on the prod hop. version + appVersion bumped in lockstep per existing convention.

🤖 Generated with Claude Code

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Note

Low Risk
Single-file metadata bump with no behavioral or deployment logic changes.

Overview
Bumps client/Chart.yamlversion and appVersion from 1.9.6 to 1.9.7 in lockstep so the release train can cut v1.9.7-rc.N on staging and stable v1.9.7 on prod.

No chart templates, values, or application code change in this diff—only the declared chart release identity.

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