Add size-first encode defaults

[shiny-code-bot]

Objective

Add explicit size-first encode defaults to Mediaforce config/runtime settings and make the assistant/folder workflow consume those defaults as product intent.

This is the first correction slice: it does not replace ab-av1, but it stops treating VMAF-only target search as the center of the workflow.

Finish Line

Config, settings, and tuning context carry explicit size-first defaults.

Current Status

State: Active
Next action: Finish full frontend/acceptance validation and open PR from correct-encoding-decision-model.
Blocked by: None
Waiting for: Full local gate result.
Last verified: 2026-05-27, focused backend tests and svelte-check passed after implementing size-first defaults.

Scope

• In: config/defaults.toml, mediaforce/web/settings_runtime.py, tuning payload/toolbelt context, Svelte settings/folder helper types, docs, and focused tests.
• Out: New encoder binaries, DB migrations, full review-gate rewrite.

Acceptance Criteria

• Defaults expose target size MB and typical episode runtime minutes.
• Defaults expose review model/mode naming that makes current ab-av1 path a fast sample mode.
• Runtime settings preserves old payloads and normalizes new fields.
• Assistant tuning payload sees the defaults so default/size-first requests use operator preference.
• UI readouts use size-target language instead of implying metrics are the goal.

Relationships

Part of #101.

Validation

• uv run --with pytest pytest tests/test_tuning_runtime.py tests/test_encode_queue_recovery.py
• npm --prefix frontend run test:unit -- --run
• npm --prefix frontend run check

Decisions

• Existing VMAF/XPSNR fields stay as guardrails for compatibility.
• Default resolution remains max_height = 1080 unless the operator requests otherwise.

Open Questions

None for this slice.

[shiny-code-bot]

Status update: implementation branch correct-encoding-decision-model is committed and PR #105 is open.

Completed in this slice:

• size-first defaults are DB/runtime-settings backed: 300 MB per 45 minutes, max 1080p, VMAF floor 80, ab-av1 fast sample engine
• Settings exposes the new defaults and the live browser view was checked at http://127.0.0.1:8777/settings
• folder tuning runtime now includes decision_defaults so assistant proposals see the size-first goal and treat metrics as guardrails
• prompts now explicitly instruct the assistant to honor the size-first default and direct operator requests instead of negotiating back to the old quality-first behavior
• /review-media serving is hardened after web smoke exposed a missing review directory failure

Validation: bash scripts/pre-commit-check.sh passed. PyCharm changed-files closeout ran; remaining findings are pre-existing weak shadowing warnings in the broad backend recovery test file.

[shiny-code-bot]

Merged PR #105 and verified on main.
Local gate: scripts/pre-commit-check.sh passed before merge.
GitHub checks: acceptance, CodeQL, and all analysis checks passed.
Live app: backend 8777 and frontend 4173 are running; Settings shows 300 MB / 45 min / VMAF floor 80.