Groom standards/CLAUDE.md: extract reference material into skills (+ guaranteed must-have skill bundle)

Problem

standards/CLAUDE.md is ~476 lines / ~7.6k tokens, synced into every developer's ~/.claude/CLAUDE.md and loaded into every session. Much of it is rarely-relevant reference material that dilutes instruction-following on unrelated tasks. The dilution comes from procedural reference dumps, not the terse rules:

• GitHub Issue Relationships GraphQL snippets (~105 lines, ~22% of the file)
• SQL/TFVC connection how-tos
• (candidate) the verbose Smoke/Integration/E2E test-writing recipes

Note — @-imports do NOT help: imported files load eagerly into context at startup (same cost as inlining). The only real context-reduction levers are skills (load on invocation) and path-scoped rules (load when a matching file is read). Verified against Claude Code docs.

Goal

Trim standards/CLAUDE.md to terse, always-applicable rules; move reference/procedure material to on-demand skills. Target ~30% smaller always-on footprint with zero content lost — it just becomes on-demand.

Phase 0 (prerequisite): guaranteed "must-have" skill bundle

Moving reference into skills is only safe if those skills are guaranteed installed. Verified mechanism:

• Declaring plugins in settings.json enabledPlugins does NOT auto-install today (open feature request anthropic-ai/claude-code#23737); it only enables already-installed plugins / prompts during repo-trust.
• Marketplaces do auto-update by default (or per-entry "autoUpdate": true); installed plugins follow their marketplace, so once installed they stay current. Pin via marketplace #ref if needed.

Plan:

1. Add the marketplace + must-have plugin set to the team-synced standards/settings.json (setup-env already deep-merges it into ~/.claude/settings.json, so it propagates to everyone and enables auto-update):

   {
     "extraKnownMarketplaces": {
       "tzander-skills": { "source": { "source": "github", "repo": "TimZander/claude" } }
     },
     "enabledPlugins": {
       "start-work@tzander-skills": true,
       "deep-review@tzander-skills": true
     }
   }
   

2. Because enabledPlugins doesn't auto-install yet, add an idempotent install step to setup-env.sh / setup-env.ps1 that installs the must-have set (re-running enforces presence + pulls updates). Verify the non-interactive install invocation.
3. Define the must-have set explicitly. Candidates: start-work, deep-review, craft-pr, improve-stories + the new reference skills created in Phase 1.
4. When native auto-install (#23737) lands, retire the setup-env install step in favor of enabledPlugins alone.

Phase 1: extract reference into skills

• GitHub Issue Relationships GraphQL block → a skill (e.g. gh-issue-relationships); remove the section from standards/CLAUDE.md.
• SQL/TFVC connection how-tos → a skill, or fold into the existing tfvc-search skill; trim/remove the section.
• Test-writing recipes → keep the terse "when to test" rules inline; move the long "how to write" procedures (Smoke/Integration/E2E) to a skill if warranted.
• Keep inline (terse, always-applicable): naming, formatting, patterns, C# rules, secret handling, git push/config safety, branch naming, PR/review standards.

Phase 2 (optional): path-scoped rules

• Consider moving language-specific rules (e.g. the C# block) into path-scoped rules (paths: ["**/*.cs"]) so they load only when editing matching files. Caveat: path-scoped rules are documented at project .claude/rules/ scope — confirm they work at user-global ~/.claude/ before relying on them. Low priority; the C# block is small.

Acceptance criteria

• Must-have skill bundle defined and added to standards/settings.json (extraKnownMarketplaces + enabledPlugins).
• setup-env.sh / .ps1 install and update the must-have bundle idempotently.
• GitHub-Issue-Relationships GraphQL reference extracted into a skill; section removed from standards/CLAUDE.md.
• SQL/TFVC how-tos extracted/relocated; section removed or trimmed.
• standards/CLAUDE.md reduced to terse always-on rules (target ~30% smaller); no content lost (now on-demand).
• After the next setup-env run, each developer has the must-have skills installed + auto-updating and a leaner ~/.claude/CLAUDE.md.

Notes

• Per the PR Size and Splitting standard, Phase 0 should land as its own PR before Phase 1 — the reference must be guaranteed reachable before it's removed from always-on context. Phase 0 may warrant its own issue.
• Relates to the standards-hygiene theme (rollup #7774 / the ADO "AI Platform" epic).

Read standards/CLAUDE.md and standards/settings.json first, then inspect setup-env.sh and setup-env.ps1 and verify the non-interactive plugin-install invocation. Define the must-have bundle, extract the named reference sections into skills, and confirm the acceptance checklist, including a leaner CLAUDE.md and idempotent installation/update behavior.