refactor(workflows): extract discuss-phase modes/templates/advisor for progressive disclosure (closes #2551) (#2607)

* refactor(workflows): extract discuss-phase modes/templates/advisor for progressive disclosure (closes #2551)

Splits 1,347-line workflows/discuss-phase.md into a 495-line dispatcher plus
per-mode files in workflows/discuss-phase/modes/ and templates in
workflows/discuss-phase/templates/. Mirrors the progressive-disclosure
pattern that #2361 enforced for agents.

- Per-mode files: power, all, auto, chain, text, batch, analyze, default, advisor
- Templates lazy-loaded at the step that produces the artifact (CONTEXT.md
  template at write_context, DISCUSSION-LOG.md template at git_commit,
  checkpoint.json schema when checkpointing)
- Advisor mode gated behind `[ -f $HOME/.claude/get-shit-done/USER-PROFILE.md ]`
  — inverse of #2174's --advisor flag (don't pay the cost when unused)
- scout_codebase phase-type→map selection table extracted to
  references/scout-codebase.md
- New tests/workflow-size-budget.test.cjs enforces tiered budgets across
  all workflows/*.md (XL=1700 / LARGE=1500 / DEFAULT=1000) plus the
  explicit <500 ceiling for discuss-phase.md per #2551
- Existing tests updated to read from the new file locations after the
  split (functional equivalence preserved — content moved, not removed)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* fix(#2607): align modes/auto.md check_existing with parent (Update it, not Skip)

CodeRabbit flagged drift between the parent step (which auto-selects "Update
it") and modes/auto.md (which documented "Skip"). The pre-refactor file had
both — line 182 said "Skip" in the overview, line 250 said "Update it" in the
actual step. The step is authoritative. Fix the new mode file to match.

Refs: PR #2607 review comment 3127783430

* test(#2607): harden discuss-phase regression tests after #2551 split

CodeRabbit identified four test smells where the split weakened coverage:

- workflow-size-budget: assertion was unreachable (entered if-block on match,
  then asserted occurrences === 0 — always failed). Now unconditional.
- bug-2549-2550-2552: bounded-read assertion checked concatenated source, so
  src.includes('3') was satisfied by unrelated content in scout-codebase.md
  (e.g., "3-5 most relevant files"). Now reads parent only with a stricter
  regex. Also asserts SCOUT_REF exists.
- chain-flag-plan-phase: filter(existsSync) silently skipped a missing
  modes/chain.md. Now fails loudly via explicit asserts.
- discuss-checkpoint: same silent-filter pattern across three sources. Now
  asserts each required path before reading.

Refs: PR #2607 review comments 3127783457, 3127783452, plus nitpicks for
chain-flag-plan-phase.test.cjs:21-24 and discuss-checkpoint.test.cjs:22-27

* docs(#2607): fix INVENTORY count, context.md placeholders, scout grep portability

- INVENTORY.md: subdirectory note said "50 top-level references" but the
  section header now says 51. Updated to 51.
- templates/context.md: footer hardcoded XX-name instead of declared
  placeholders [X]/[Name], which would leak sample text into generated
  CONTEXT.md files. Now uses the declared placeholders.
- references/scout-codebase.md: no-maps fallback used grep -rl with
  "\\|" alternation (GNU grep only — silent on BSD/macOS grep). Switched
  to grep -rlE with extended regex for portability.

Refs: PR #2607 review comments 3127783404, 3127783448, plus nitpick for
scout-codebase.md:32-40

* docs(#2607): label fenced examples + clarify overlay/advisor precedence

- analyze.md / text.md / default.md: add language tags (markdown/text) to
  fenced example blocks to silence markdownlint MD040 warnings flagged by
  CodeRabbit (one fence in analyze.md, two in text.md, five in default.md).
- discuss-phase.md: document overlay stacking rules in discuss_areas — fixed
  outer→inner order --analyze → --batch → --text, with a pointer to each
  overlay file for mode-specific precedence.
- advisor.md: add tie-breaker rules for NON_TECHNICAL_OWNER signals — explicit
  technical_background overrides inferred signals; otherwise OR-aggregate;
  contradictory explanation_depth values resolve by most-recent-wins.

Refs: PR #2607 review comments 3127783415, 3127783437, plus nitpicks for
default.md:24, discuss-phase.md:345-365, and advisor.md:51-56

* fix(#2607): extract codebase_drift_gate body to keep execute-phase under XL budget

PR #2605 added 80 lines to execute-phase.md (1622 -> 1702), pushing it over
the XL_BUDGET=1700 line cap enforced by tests/workflow-size-budget.test.cjs
(introduced by this PR). Per the test's own remediation hint and #2551's
progressive-disclosure pattern, extract the codebase_drift_gate step body to
get-shit-done/workflows/execute-phase/steps/codebase-drift-gate.md and leave
a brief pointer in the workflow. execute-phase.md is now 1633 lines.

Budget is NOT relaxed; the offending workflow is tightened.

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/ARCHITECTURE.md

@@ -131,6 +131,33 @@ Orchestration logic that commands reference. Contains the step-by-step process i
 
 **Total workflows:** see [`docs/INVENTORY.md`](INVENTORY.md#workflows) for the authoritative count and full roster.
 
+#### Progressive disclosure for workflows
+
+Workflow files are loaded verbatim into Claude's context every time the
+corresponding `/gsd:*` command is invoked. To keep that cost bounded, the
+workflow size budget enforced by `tests/workflow-size-budget.test.cjs`
+mirrors the agent budget from #2361:
+
+| Tier      | Per-file line limit |
+|-----------|--------------------|
+| `XL`      | 1700 — top-level orchestrators (`execute-phase`, `plan-phase`, `new-project`) |
+| `LARGE`   | 1500 — multi-step planners and large feature workflows |
+| `DEFAULT` | 1000 — focused single-purpose workflows (the target tier) |
+
+`workflows/discuss-phase.md` is held to a stricter <500-line ceiling per
+issue #2551. When a workflow grows beyond its tier, extract per-mode bodies
+into `workflows/<workflow>/modes/<mode>.md`, templates into
+`workflows/<workflow>/templates/`, and shared knowledge into
+`get-shit-done/references/`. The parent file becomes a thin dispatcher that
+Reads only the mode and template files needed for the current invocation.
+
+`workflows/discuss-phase/` is the canonical example of this pattern —
+parent dispatches, modes/ holds per-flag behavior (`power.md`, `all.md`,
+`auto.md`, `chain.md`, `text.md`, `batch.md`, `analyze.md`, `default.md`,
+`advisor.md`), and templates/ holds CONTEXT.md, DISCUSSION-LOG.md, and
+checkpoint.json schemas that are read only when the corresponding output
+file is being written.
+
 ### Agents (`agents/*.md`)
 
 Specialized agent definitions with frontmatter specifying:

docs/INVENTORY-MANIFEST.json

@@ -242,6 +242,7 @@
       "project-skills-discovery.md",
       "questioning.md",
       "revision-loop.md",
+      "scout-codebase.md",
       "sketch-interactivity.md",
       "sketch-theme-system.md",
       "sketch-tooling.md",

docs/INVENTORY.md

@@ -269,7 +269,7 @@ Full roster at `get-shit-done/workflows/*.md`. Workflows are thin orchestrators
 
 ---
 
-## References (50 shipped)
+## References (51 shipped)
 
 Full roster at `get-shit-done/references/*.md`. References are shared knowledge documents that workflows and agents `@-reference`. The groupings below match [`docs/ARCHITECTURE.md`](ARCHITECTURE.md#references-get-shit-donereferencesmd) — core, workflow, thinking-model clusters, and the modular planner decomposition.
 
@@ -303,6 +303,7 @@ Full roster at `get-shit-done/references/*.md`. References are shared knowledge
 | `continuation-format.md` | Session continuation/resume format. |
 | `domain-probes.md` | Domain-specific probing questions for discuss-phase. |
 | `gate-prompts.md` | Gate/checkpoint prompt templates. |
+| `scout-codebase.md` | Phase-type→codebase-map selection table for discuss-phase scout step (extracted via #2551). |
 | `revision-loop.md` | Plan revision iteration patterns. |
 | `universal-anti-patterns.md` | Universal anti-patterns to detect and avoid. |
 | `artifact-types.md` | Planning artifact type definitions. |
@@ -354,7 +355,7 @@ The `gsd-planner` agent is decomposed into a core agent plus reference modules t
 | `planner-revision.md` | Plan revision patterns for iterative refinement. |
 | `planner-source-audit.md` | Planner source-audit and authority-limit rules. |
 
-> **Subdirectory:** `get-shit-done/references/few-shot-examples/` contains additional few-shot examples (`plan-checker.md`, `verifier.md`) that are referenced from specific agents. These are not counted in the 50 top-level references.
+> **Subdirectory:** `get-shit-done/references/few-shot-examples/` contains additional few-shot examples (`plan-checker.md`, `verifier.md`) that are referenced from specific agents. These are not counted in the 51 top-level references.
 
 ---