feat: report actual IDE for session tracking

[EhabY]

Summary

• Report vscode.env.uriScheme verbatim through --usage-app and CODER_SSH_SESSION_TYPE when both CLI and server support custom session app names (2.38+).
• Otherwise use vscode, including unreadable CLI versions, without changing unrelated compatibility fallbacks.
• Pass SSH configuration inputs through one options object. Separate app-selection tests from real in-memory SSH configuration checks.

Implements CLIENT-643.

Validation

• Latest revision: typecheck, lint, formatting, and diff checks passed.
• Before the latest test/SSH-options simplification: 43 focused tests passed; extension/webview build passed earlier.
• Test execution skipped for the latest revision at request. Full suite previously interrupted by workspace disconnection; live deployment attribution not verified.

Approved plan and compatibility decisions

1. Gate customSessionAppNames in existing CLI/server feature sets at 2.38.0, retaining the existing development-build convention.
2. Resolve one app name from both capabilities. Fall back conservatively if CLI probing fails while preserving unrelated server-version fallbacks.
3. Pass SSH configuration through SshConfigOptions; use the same name for both reporting mechanisms. Leave vscodessh unchanged and normalize only on the server.
4. Cover compatibility boundaries with a small table, CLI-probe failure separately, and generated SSH values with focused in-memory config tests. No editor-brand mapping or branching test matrix.

Keep both signals: the workspace-usage experiment uses CLI usage requests for counts when enabled, and agent stats when disabled. Its proposed removal (coder/coder#30206) remains a draft and retains the usage flag. The CLI/server gate does not guarantee the workspace agent has been upgraded.

Generated by Coder Agents on behalf of @EhabY.

[linear-code]

CLIENT-643