feat(gateway): system prompt profiles UI with CRUD, section options, model overrides

[penso]

Summary

• Profile CRUD: create, delete, and set-default prompt profiles from the settings UI via new system_prompt.config.create, .delete, .set_default RPC methods
• Section Options panel: toggle runtime fields, user details mode, memory bootstrap options, and datetime tail mode per profile — changes reflected in live preview
• Enabled Sections grid: enable/disable individual prompt sections per profile (required sections locked)
• Model Overrides UI: route specific providers/models to different prompt profiles using glob patterns (e.g. *sonnet*, openai), with reorderable list, add/remove, and save via system_prompt.config.overrides.save RPC
• Schema simplification: flatten PromptProfileOverride TOML schema — provider and model are now top-level fields instead of nested under [match] (backward compatible)
• Polish: collapsible template variables (hidden by default), preview profile name display, inline style → Tailwind migration, indentation fix
• Tests: scope authorization tests for all new RPCs, unit tests for apply_section_options and parse_enabled_sections, 5 new E2E tests

Validation

Completed

• biome check --write (JS)
• cargo +nightly-2025-11-30 fmt --all -- --check (Rust)
• cargo +nightly-2025-11-30 clippy --workspace --all-targets -- -D warnings
• cargo test (all pass, 499 gateway tests)
• Tailwind CSS rebuilt
• Merged main, no conflicts

Remaining

• ./scripts/local-validate.sh
• E2E playwright tests (npx playwright test)

Manual QA

1. Navigate to Settings → System Prompt
2. Create a new profile, verify it appears in the dropdown
3. Set the new profile as default, verify label updates
4. Delete a non-default profile
5. Toggle Section Options (runtime checkboxes, user details mode, memory options, datetime tail mode) — verify live preview updates
6. Toggle enabled sections in the grid — verify required sections are locked
7. Expand Model Overrides, add an override with provider/model globs, reorder, save
8. Reload page — verify overrides persist
9. Expand/collapse Template Variables list
10. Verify existing TOML configs with [[prompt_profiles.overrides]] using [match] tables still work (backward compat)

[codspeed-hq]

Merging this PR will degrade performance by 12.02%

❌ 2 regressed benchmarks
✅ 37 untouched benchmarks
⏩ 5 skipped benchmarks¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	config_validate_toml	1.9 ms	2.2 ms	-12.02%
❌	full_config_boot_path	3.2 ms	3.6 ms	-11.13%

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_{Comparing settings-system-prompt (5c53dfd) with main (38b8ca1)}

Footnotes

1. 5 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[codecov]

Codecov Report

❌ Patch coverage is 79.41176% with 350 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
crates/gateway/src/methods.rs	35.51%	305 Missing ⚠️
crates/gateway/src/chat.rs	91.98%	25 Missing ⚠️
crates/agents/src/prompt.rs	97.44%	20 Missing ⚠️

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