Task: Unified tenor resolution: tenor_schedules, SCHEDULE_STEP resolver, RATES_SPOT_FOMC, 1F..nF

Implement the unified tenor resolution model from the FOMC analysis (story * Decisions D2): a tenor resolves as anchor + a calendar offset + n steps along a named schedule axis. Calendar arithmetic (ANCHOR_OFFSET) stays as-is; a new SCHEDULE_STEP algorithm walks a named schedule from the tenor_schedules vocabulary – ROLL_QUARTER (closed-form IMM rule, code-side) and FOMC_MEETING (event-lookup into US.FOMC / central_bank_meeting events). IMM and FOMC become the same mechanism; the old IMM_ROLL algorithm row is superseded.

• tenor_schedules entity (ores.refdata, codegen'd): code, name, description, display_order, schedule_source, calendar_code, diary_entry_type; seeded ROLL_QUARTER (CLOSED_FORM) and FOMC_MEETING (EVENT_LOOKUP on US.FOMC / central_bank_meeting).
• tenor_resolution_algorithms gains SCHEDULE_STEP; tenor_resolution.cpp implements walk(anchor + calendar offset, schedule, steps) for both schedule sources; the old IMM_ROLL / ROLL_QUARTER logic_error paths are gone.
• tenor_convention_resolutions gains nullable schedule_code and schedule_step_count; offset columns remain the calendar-axis offset.
• RATES_SPOT_FOMC convention (measured_from SPOT, algorithm SCHEDULE_STEP, schedule FOMC_MEETING) with tenors 1F..nF (kind SPECIAL, unit NONE, multiplier n) and resolution rows schedule_step_count = n, resolving to the n-th meeting on-or-after spot.
• CREDIT_CDS_IMM migrates to (SCHEDULE_STEP, ROLL_QUARTER) with offset YEAR x 1 and 1 schedule step ('1Y 1RQ'); the IMM_ROLL algorithm row is removed from populate once nothing references it; the IMM_ROLL anchor (measured_from) stays.
• Unit tests cover both schedules (closed-form roll stepping and event lookup) plus the migrated CDS convention.

(Implementation strategy. Written when work starts; key decisions are distilled into the parent story's * Decisions at close, but the plan itself stays — it is the historical record of what we did.)

• Junction codegen clobbering (2026-08-10): re-running codegen entity generate on a junction model overwrites the hand-authored messaging layer (protocol request structs, handler list, read-only service) with template stubs and drops the tenant profile when :profile: is a top-level keyword instead of a * Flags drawer property. Recovery procedure used here: move the profile into the * Flags drawer, regenerate, restore the four hand-authored files from HEAD, delete the generated junction sub-registrar (unreferenced; the aggregate registrar wires the junction inline per its own comment), and re-run regenerate_cmake_component_files.py so the directory scan drops the dead entries.
• The exhaustion test (9F > 8 meetings) initially passed vacuously: std::invalid_argument derives from std::logic_error, so CHECK_THROWS_AS matched the wrong throw. The fixture fix (SPECIAL offset columns on the FOMC rows) makes the walk genuinely exercise the exhaustion path.
• CREDIT_CDS_IMM '1Y 1RQ' semantics: this catalog's one-year label is 12M (MONTH x 12), not 1Y; the migration rows use 12M, 2Y, 3Y, 5Y, 7Y, 10Y with schedule_step_count = 1.

Manual QA scenarios (scaffolded via compass add test_scenario, run through the QA Validation Runner panel) that verify this task. Link new ones here as they're created; the scenario doc itself links back via its "Verifies task" field.

Done. The unified resolution model is implemented end to end and all three suites are green:

• tenor_schedules entity (code, name, description, display_order, schedule_source, calendar_code, diary_entry_type) modelled via compass add entity_org, codegen'd across api/core/service/qt/sql; seeded ROLL_QUARTER (CLOSED_FORM) and FOMC_MEETING (EVENT_LOOKUP on US.FOMC / central_bank_meeting).
• tenor_resolution_algorithms gains SCHEDULE_STEP; the old IMM_ROLL row is removed and the ROLL_QUARTER logic_error path in add_offset is gone.

• tenor_resolution.cpp implements the walk: anchor + calendar offset

  • n steps. ROLL_QUARTER steps are closed-form IMM dates (first

  business day on-or-after the 20th of Mar/Jun/Sep/Dec, code-side); FOMC_MEETING steps walk caller-supplied event dates. Missing schedule fields or exhaustion report as std::logic_error; unrecognised algorithms as std::invalid_argument.

• resolve_end_date gains a defaulted optional schedule-dates parameter; all existing callers compile unchanged.
• tenor_convention_resolutions gains nullable schedule_code / schedule_step_count; RATES_SPOT_FOMC (SPOT, SCHEDULE_STEP, FOMC_MEETING) seeds 1F..8F (SPECIAL, NONE x n, DAY x 0 offset, n steps); CREDIT_CDS_IMM migrates to (SCHEDULE_STEP, ROLL_QUARTER) with anchor_override SPOT and one roll-quarter step ('1Y 1RQ').
• Test updates: the two red SCHEDULE_STEP dispatch tests and the exhaustion test are green; a ROLL_QUARTER closed-form walk test and the migrated-CDS pinned-date test are added (74/74 refdata, 369 assertions); marketdata 24/24 (164) and quant 372/372 (2.1M) unaffected and green.
• tenor_convention_resolution.org profile moved into the * Flags drawer, restoring the tenant_id column to entity, SQL and repository.