feat(agents): add Hephaestus - autonomous deep worker agent (#1287)

* refactor(keyword-detector): split constants into domain-specific modules

* feat(shared): add requiresAnyModel and isAnyFallbackModelAvailable

* feat(config): add hephaestus to agent schemas

* feat(agents): add Hephaestus autonomous deep worker

* feat(cli): update model-fallback for hephaestus support

* feat(plugin): add hephaestus to config handler with ordering

* test(delegate-task): update tests for hephaestus agent

* docs: update AGENTS.md files for hephaestus

* docs: add hephaestus to READMEs

* chore: regenerate config schema

* fix(delegate-task): bypass requiresModel check when user provides explicit config

* docs(hephaestus): add 4-part context structure for explore/librarian prompts

* docs: fix review comments from cubic (non-breaking changes)

- Move Hephaestus from Primary Agents to Subagents (uses own fallback chain)
- Fix Hephaestus fallback chain documentation (claude-opus-4-5 → gemini-3-pro)
- Add settings.local.json to claude-code-hooks config sources
- Fix delegate_task parameters in ultrawork prompt (agent→subagent_type, background→run_in_background, add load_skills)
- Update line counts in AGENTS.md (index.ts: 788, manager.ts: 1440)

* docs: fix additional documentation inconsistencies from oracle review

- Fix delegate_task parameters in Background Agents example (docs/features.md)
- Fix Hephaestus fallback chain in root AGENTS.md to match model-requirements.ts

* docs: clarify Hephaestus has no fallback (requires gpt-5.2-codex only)

Hephaestus uses requiresModel constraint - it only activates when gpt-5.2-codex
is available. The fallback chain in code is unreachable, so documentation
should not mention fallbacks.

* fix(hephaestus): remove unreachable fallback chain entries

Hephaestus has requiresModel: gpt-5.2-codex which means the agent only
activates when that specific model is available. The fallback entries
(claude-opus-4-5, gemini-3-pro) were unreachable and misleading.

---------

Co-authored-by: justsisyphus <justsisyphus@users.noreply.github.com>

src/hooks/keyword-detector/detector.ts

@@ -17,26 +17,27 @@ export function removeCodeBlocks(text: string): string {
  * Resolves message to string, handling both static strings and dynamic functions.
  */
 function resolveMessage(
-  message: string | ((agentName?: string) => string),
-  agentName?: string
+  message: string | ((agentName?: string, modelID?: string) => string),
+  agentName?: string,
+  modelID?: string
 ): string {
-  return typeof message === "function" ? message(agentName) : message
+  return typeof message === "function" ? message(agentName, modelID) : message
 }
 
-export function detectKeywords(text: string, agentName?: string): string[] {
+export function detectKeywords(text: string, agentName?: string, modelID?: string): string[] {
   const textWithoutCode = removeCodeBlocks(text)
   return KEYWORD_DETECTORS.filter(({ pattern }) =>
     pattern.test(textWithoutCode)
-  ).map(({ message }) => resolveMessage(message, agentName))
+  ).map(({ message }) => resolveMessage(message, agentName, modelID))
 }
 
-export function detectKeywordsWithType(text: string, agentName?: string): DetectedKeyword[] {
+export function detectKeywordsWithType(text: string, agentName?: string, modelID?: string): DetectedKeyword[] {
   const textWithoutCode = removeCodeBlocks(text)
   const types: Array<"ultrawork" | "search" | "analyze"> = ["ultrawork", "search", "analyze"]
   return KEYWORD_DETECTORS.map(({ pattern, message }, index) => ({
     matches: pattern.test(textWithoutCode),
     type: types[index],
-    message: resolveMessage(message, agentName),
+    message: resolveMessage(message, agentName, modelID),
   }))
     .filter((result) => result.matches)
     .map(({ type, message }) => ({ type, message }))