I3235 — The site generator reads the use-case catalogue once per run

✕BLOCKED wave 3 · p2 · implementation profile · parallel safe

Part of a-change-is-judged-in-minutes — A change is derived in under a second and judged in minutes, and nothing that could have changed is skipped.

Objective

Parse the use-case catalogue once in scripts/generate-site-data and hand the parsed form to every section that needs it, with output byte-identical.

Why

Board p3 (Codex) audit 2026-10-18: stage B parses the catalogue four times. Rule project.hot-path-reads-once. Past derive wins came from removing repeated passes and spawns (c265#8). It extends milestone M004. Sources: chatgpt-majordomus:c292#2.

Current state

scripts/generate-site-data is 2638 lines (wc -l on master 707a04c, 2026-10-18). The board p3 audit (2026-10-18) counted four parses of the use-case catalogue per run; that count is the audit's, not re-measured here. I0832 'generate-site-data instrumented and its hot spots removed' (READY, p0) times the generator's phases and removes the repeated work in its two most expensive sections; this issue is the catalogue-parse delta on top of it.

Desired state

One parse per run, counted by MJ_TIMING work counters.

Scope

• scripts/generate-site-data
• test/cases/10_site_data.sh

Out of scope

• Scenario reuse (I2526)
• Porting the generator off shell
• Phase timing and ranking of the generator, and its two most expensive sections (I0832)

Dependencies

• I2521○READY What a derive costs is measured per stage and per kind of change, and every file a stage reads is listed
• I0832○READY generate-site-data instrumented and its hot spots removed

Acceptance criteria

• The work counter shows one catalogue parse per run
• Site data is byte-identical before and after
• generate-site-data --check passes

Validation

• MJ_TIMING=1 scripts/generate-site-data --check
• bash test/run.sh 10_site_data

Evidence required

• catalogue_read_once_counter

Evidence

None recorded. Every token above needs a command or an artifact behind it before this issue can be completed; narrative is refused.

Timeline

started

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verified

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completed

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Those three fields, the evidence above and the state of the dependencies are all the status is made of. There is no status field to disagree with them.

Canonical record: .ai/repo/project/issues/I3235.yaml. Read it back with majordomus plan show I3235.