Grilling: apply hard gates and draft rejection appendix

[Skymly]

Part of #244

Question

Using the merged longlist from the five family researches plus the F3 pool / shipped-domain inventory: which candidates fail any of the three F3 hard gates, and which pass into the ranking pool?

Hard gates (must all pass):

1. Expressible as lightweight primitive + compile-time glue (not a heavyweight base-class framework).
2. Meaningful compile-time exploration value (generator / diagnostics / DI), even if runtime overlaps ecosystem libraries.
3. Real usage scenario + at least one Sample sketch.

Record: passers list + rejection appendix (candidate → failed gate → one-line why). Lock this with the maintainer before ranking.

[Skymly]

Resolution

Hard gates applied on the merged longlist (map #244). Passers enter the ranking pool for #252/#253; failures go to the rejection appendix.

Consolidation (pre-gates)

• Command / F3 Command routing / Command Router → Command Router
• F3 Resilience primitive → absorbed into resilience-family concrete candidates (no free-floating item)
• Request Pipeline Behaviors / Stream Request Router → domain capabilities of Command Router (not separate domains)
• Interpreter / Query Object → fold into Specification (not independent domains)
• Circuit Breaker Gate / Fallback Provider Chain → features of Compile-time Resilience Pipeline if admitted (not separate domains)

Passers (ranking pool)

1. Builder
2. Command Router
3. Compile-time Resilience Pipeline
4. Specification
5. Channel Pipeline
6. Fork–Join Work Graph
7. Proxy

Rejection appendix

Candidate	Failed gate / reason
Observer / lightweight pub-sub	Not a new domain (Event Aggregator enhancement)
ObjectPool	Not a new domain (Factory Registry pooling already exists)
Named Resilience Policy Registry	Not a distinct domain (Strategy-registry-shaped)
Phased Barrier Coordination	Gates 1/2 — thin BCL Barrier/CountdownEvent façade
Interpreter	Fold into Specification
Query Object	Fold into Specification / weak distinct glue
Circuit Breaker Gate	Not standalone — pipeline step
Fallback Provider Chain	Not standalone — pipeline/Chain-shaped step
Request Pipeline Behaviors	Fold into Command Router
Stream Request Router	Fold into Command Router / weak Sample as standalone
Correlated Request/Reply Messenger	Thin compile-time surface
Abstract Factory	Conflicts with Factory Registry “no product families” stance
Actor Mailbox	Gate 1 — hard to keep as lightweight primitive
Production Ruleset	Spec + ordered effects; insufficient independent domain

Research notes remain on research/* branches under docs/.Local/research/.

[Skymly]

Hard gates locked with maintainer: 7 passers (Builder, Command Router, Compile-time Resilience Pipeline, Specification, Channel Pipeline, Fork–Join Work Graph, Proxy) + rejection appendix in resolution comment.