chore: Release hotdata-cli version 0.4.0

[eddietejeda]

Prepares the 0.4.0 release.

Changes

• Bump version to 0.4.0 in Cargo.toml / Cargo.lock
• Update README version badge
• Update all skill versions to 0.4.0
• Add CHANGELOG entry

Included since 0.3.4

• feat(databases): add --catalog flag to databases create (feat(databases): add --catalog flag to databases create #125)
• feat(queries): show result_id in queries list table (feat(queries): show result_id in queries list table #126)
• feat: managed database demo flow — explicit flags, catalog resolution, BM25 search (feat: managed database demo flow — explicit flags, catalog resolution, BM25 search #127)

After merging, tag the resulting commit with v0.4.0 to trigger the release workflow.

[claude]

Release PR looks clean. Version bumped consistently to 0.4.0 across Cargo.toml, Cargo.lock, README badge, and all four skill files. CHANGELOG entry matches the three included PRs (#125, #126, #127). No lingering 0.3.4 references outside CHANGELOG history.

[sentry]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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