refactor(aidd-context): citations are markdown links at their point of use

[blafourcade]

🎯 What & why

Two claims were reported against aidd-context:04-skill-generate: it never says to use markdown links, and never says to cite a reference at the point it is used. The first is half true, the second is true. Fixing the contract exposed that the rule was never applied outside the two skills a July migration touched, so 143 citations across six plugins still used a notation nothing reads.

🛠️ How it works

Commit 1 rewrites the contract. skill-authoring.md R6 covered only what an action cites from a reference, and said nothing about placement. It now covers assets too and requires a citation to sit where it is used, never gathered in a list of its own. R8 gains the counterpart it always implied: a reference names a sibling, never links it.

Three deliberate scope calls:

• Placement is "where it is used", not "inside a ## Process step" — which is weaker than reported, on purpose. Three of skill-generate's own actions cite from ## Output or ## Test at their point of use (01-scope.md:19). The strict rule would make 04-validate flag its own source.
• Scoped to actions, not the router. grep '](\.\|@' plugins/*/skills/*/SKILL.md returns nothing; the action table names slugs on purpose.
• R2's naming.md stays in backticks. A global link rule would force a reference to link a sibling, which R8 forbids.

Commit 2 migrates the fleet. 7661980 converted skill-generate and project-memory only, as its own message states. Both are still at zero; nothing regressed. Everything else was never in scope and inherited nothing, because skill-authoring.md is local to 04-skill-generate.

143 citations, three shapes:

Shape	Count	Action
Inline `@../references/x.md`	133	converted one for one, surrounding punctuation kept, no sentence restructured
Bare @path alone in a fenced block	8	inlined into the step that consumes it, fence removed
@ as a literal character	1	untouched
A glob, @../assets/recipes/*.md	1	@ dropped, backticks kept — a glob is not a citation

The eight fenced ones were first carved out as "load mechanics". That was wrong: nothing parses them, a link inside a fence renders as literal text, and 02-upsert.md stacked three of them in a block above ## Input with no step naming any — the exact shape R6 now forbids.

Out of scope: @claude in the orchestrator routing regex and @playwright/mcp in a cook recipe. Neither is a citation.

Full reasoning and the counts behind each decision: proposal.md.

🧪 How to verify

• grep -rn '@\.\.\?/' plugins/ → empty.
• The markdown-links pre-commit hook passes: 0 broken in 561 files. The two pre-existing failures in plan-template.md are scaffold placeholders in an untouched asset.
• Read 08-hook-generate/actions/02-write-hook.md before and after — four citations per step, now clickable.

⚠️ Heads-up

skill-authoring.md stays local to 04-skill-generate. The other generators (05-rule-generate, 06-agent-generate, 07-command-generate, 08-hook-generate) each carry their own *-authoring.md and inherit nothing, so R6 does not reach what they emit. This conversion holds until one of them generates the next skill. Propagating the contract is a separate subject, not folded in here.

✅ I certify

• I DO CERTIFY I READ EACH LINE OF THE PULL REQUEST BECAUSE I AM A SOFTWARE ENGINEER, NOT A AI PUPPY.