docs: close doc drift vectors — bidirectional parity, manifest, schema-driven config (#2479)

Option A — ghost-entry guard (INVENTORY ⊆ actual):
  tests/inventory-source-parity.test.cjs parses every declared row in
  INVENTORY.md and asserts the source file exists. Catches deletions and
  renames that leave ghost entries behind.

Option B — auto-generated structural manifest:
  scripts/gen-inventory-manifest.cjs walks all six family dirs and emits
  docs/INVENTORY-MANIFEST.json. tests/inventory-manifest-sync.test.cjs
  fails CI when a new surface ships without a manifest update, surfacing
  exactly which entries are missing.

Option C — schema-driven config validation + docs parity:
  get-shit-done/bin/lib/config-schema.cjs extracted from config.cjs as
  the single source of truth for VALID_CONFIG_KEYS and dynamic patterns.
  config.cjs now imports from it. tests/config-schema-docs-parity.test.cjs
  asserts every exact-match key appears in docs/CONFIGURATION.md, surfacing
  14 previously undocumented keys (planning.sub_repos, workflow.ai_integration_phase,
  git.base_branch, learnings.max_inject, and 10 others) — all now documented
  in their appropriate sections.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/CONFIGURATION.md

@@ -113,6 +113,12 @@ GSD stores project settings in `.planning/config.json`. Created during `/gsd-new
 | `response_language` | string | language code | (none) | Language for agent responses (e.g., `"pt"`, `"ko"`, `"ja"`). Propagates to all spawned agents for cross-phase language consistency. Added in v1.32 |
 | `context_profile` | string | `dev`, `research`, `review` | (none) | Execution context preset that applies a pre-configured bundle of mode, model, and workflow settings for the current type of work. Added in v1.34 |
 | `claude_md_path` | string | any file path | `./CLAUDE.md` | Custom output path for the generated CLAUDE.md file. Useful for monorepos or projects that need CLAUDE.md in a non-root location. Defaults to `./CLAUDE.md` at the project root. Added in v1.36 |
+| `context` | string | any text | (none) | Custom context string injected into every agent prompt for the project. Use to provide persistent project-specific guidance (e.g., coding conventions, team practices) that every agent should be aware of |
+| `phase_naming` | string | any string | (none) | Custom prefix for phase directory names. When set, overrides the auto-generated phase slug (e.g., `"feature"` produces `feature-01-setup/` instead of the roadmap-derived slug) |
+| `brave_search` | boolean | `true`/`false` | auto-detected | Override auto-detection of Brave Search API availability. When unset, GSD checks for `BRAVE_API_KEY` env var or `~/.gsd/brave_api_key` file |
+| `firecrawl` | boolean | `true`/`false` | auto-detected | Override auto-detection of Firecrawl API availability. When unset, GSD checks for `FIRECRAWL_API_KEY` env var or `~/.gsd/firecrawl_api_key` file |
+| `exa_search` | boolean | `true`/`false` | auto-detected | Override auto-detection of Exa Search API availability. When unset, GSD checks for `EXA_API_KEY` env var or `~/.gsd/exa_api_key` file |
+| `search_gitignored` | boolean | `true`/`false` | `false` | Legacy top-level alias for `planning.search_gitignored`. Prefer the namespaced form; this alias is accepted for backward compatibility |
 
 > **Note:** `granularity` was renamed from `depth` in v1.22.3. Existing configs are auto-migrated.
 
@@ -148,6 +154,11 @@ All workflow toggles follow the **absent = enabled** pattern. If a key is missin
 | `workflow.cross_ai_execution` | boolean | `false` | Delegate phase execution to an external AI CLI instead of spawning local executor agents. Useful for leveraging a different model's strengths for specific phases. Added in v1.36 |
 | `workflow.cross_ai_command` | string | (none) | Shell command template for cross-AI execution. Receives the phase prompt via stdin. Must produce SUMMARY.md-compatible output. Required when `cross_ai_execution` is `true`. Added in v1.36 |
 | `workflow.cross_ai_timeout` | number | `300` | Timeout in seconds for cross-AI execution commands. Prevents runaway external processes. Added in v1.36 |
+| `workflow.ai_integration_phase` | boolean | `true` | Enable the `/gsd-ai-integration-phase` command. When `false`, the command exits with a configuration gate message |
+| `workflow.auto_prune_state` | boolean | `false` | When `true`, automatically prune stale entries from STATE.md at phase boundaries instead of prompting |
+| `workflow.pattern_mapper` | boolean | `true` | Run the `gsd-pattern-mapper` agent between research and planning to map new files to existing codebase analogs |
+| `workflow.subagent_timeout` | number | `600` | Timeout in seconds for individual subagent invocations. Increase for long-running research or execution phases |
+| `workflow.inline_plan_threshold` | number | `3` | Maximum number of tasks in a phase before the planner generates a separate PLAN.md file instead of inlining tasks in the prompt |
 
 ### Recommended Presets
 
@@ -266,6 +277,7 @@ Toggle optional capabilities via the `features.*` config namespace. Feature flag
 |---------|------|---------|-------------|
 | `features.thinking_partner` | boolean | `false` | Enable thinking partner analysis at workflow decision points |
 | `features.global_learnings` | boolean | `false` | Enable cross-project learnings pipeline (auto-copy at phase completion, planner injection) |
+| `learnings.max_inject` | number | `10` | Maximum number of cross-project learnings injected into each planner prompt. Lower values reduce prompt size; higher values provide broader historical context |
 | `intel.enabled` | boolean | `false` | Enable queryable codebase intelligence system. When `true`, `/gsd-intel` commands build and query a JSON index in `.planning/intel/`. Added in v1.34 |
 
 <a id="graphify-settings"></a>
@@ -294,6 +306,7 @@ The `features.*` namespace is a dynamic key pattern — new feature flags can be
 
 | Setting | Type | Default | Description |
 |---------|------|---------|-------------|
+| `parallelization` | boolean | `true` | Shorthand for `parallelization.enabled`. Setting `parallelization false` disables parallel execution without changing other sub-keys |
 | `parallelization.enabled` | boolean | `true` | Run independent plans simultaneously |
 | `parallelization.plan_level` | boolean | `true` | Parallelize at plan level |
 | `parallelization.task_level` | boolean | `false` | Parallelize tasks within a plan |
@@ -310,6 +323,7 @@ The `features.*` namespace is a dynamic key pattern — new feature flags can be
 | Setting | Type | Default | Description |
 |---------|------|---------|-------------|
 | `git.branching_strategy` | enum | `none` | `none`, `phase`, or `milestone` |
+| `git.base_branch` | string | `main` | The integration branch that phase/milestone branches are created from and merged back into. Override when your repo uses `master` or a release branch |
 | `git.phase_branch_template` | string | `gsd/phase-{phase}-{slug}` | Branch name template for phase strategy |
 | `git.milestone_branch_template` | string | `gsd/{milestone}-{slug}` | Branch name template for milestone strategy |
 | `git.quick_branch_template` | string or null | `null` | Optional branch name template for `/gsd-quick` tasks |