Feature/aproximate freq from sds

[arneschmid]

Fixes

• #

Infer missing SDS sample frequency and add strict parsing controls

Changes

• Added SDS parser strictness options with warnings for lenient parsing of incomplete trailing records.
• Added metadata parsing options to allow or infer missing sample-frequency from an associated SDS file.
• Updated SDS viewers to tolerate live/truncated SDS files and infer missing sample frequency.
• Updated explorer media detection to allow missing sample frequency without scanning SDS data.
• Added .cmsis-dev/* to .gitignore.
• Updated unit tests for parser, metadata, viewer, explorer, and CSV export behavior.

Why

• Supports SDS metadata that omits sample-frequency while preserving viewer usability for files that may still be recording or partially written.
• Makes corrupt/truncated SDS handling explicit at parser call sites.

Risk / Follow-up

• SDS parsing is now strict by default, so callers that do not opt into lenient parsing may fail on trailing incomplete records.
• Sample-frequency inference reads SDS data synchronously and depends on enough valid timestamp deltas; large or truncated files may need further hardening.

Screenshots

Checklist

• 🤖 This change is covered by unit tests (if applicable).
• 🤹 Manual testing has been performed (if necessary).
• 🛡️ Security impacts have been considered (if relevant).
• 📖 Documentation updates are complete (if required).
• 🧠 Third-party dependencies and TPIP updated (if required).