G-087: thin project layouts goal - index entry + detail file (active)

New goal from the 2026-07-16 layout-system review: thin layouts with
generation-time infrastructure injection, fauxlink layout refs, and a working
overlay merge primitive. Detail file carries the review findings (unimplemented
merge, dead module-pathtype refs, stale fat snapshots, latent bugs), the staged
approach (hygiene first), and the hygiene-stage completion record.
Activated at user direction 2026-07-17.

Assisted-by: harness=claude; primary-model=claude-fable-5; api-location=anthropic.com

GOALS.md

@@ -325,3 +325,7 @@ Detail: goals/G-085-cmdtrace-attribution-and-machine-output.md
 ### G-086 [proposed] Light project layout: punkshell-generated minimal projects carrying startup/test module-path semantics
 Scope: src/project_layouts/ (new light layout), src/modules/punk/mix/commandset/project-999999.0a1.0.tm (project.new layout selection), layout-seeded test harness + startup preamble (no bootsupport/vfs/build trees in generated output)
 Detail: goals/G-086-light-project-layout.md
+
+### G-087 [active] Thin project layouts: injected infrastructure, fauxlink layout refs, working overlay merge
+Scope: src/project_layouts/ (payload store restructure), src/decktemplates/ (layout_refs migration to fauxlink), src/modules/punk/mix/commandset/project-999999.0a1.0.tm (project.new generation path), src/modules/punk/mix/commandset/layout-999999.0a1.0.tm, src/modules/punk/cap/handlers/templates-999999.0a1.0.tm (ref resolution), src/modules/punk/mix/#modpod-templates-999999.0a1.0/ (module-shipped refs/layouts), src/make.tcl (layout sync steps)
+Detail: goals/G-087-thin-project-layouts.md

goals/G-087-thin-project-layouts.md

@@ -0,0 +1,202 @@
+# G-087 Thin project layouts: injected infrastructure, fauxlink layout refs, working overlay merge
+
+Status: active
+Scope: src/project_layouts/ (payload store restructure), src/decktemplates/ (layout_refs migration to fauxlink), src/modules/punk/mix/commandset/project-999999.0a1.0.tm (project.new generation path), src/modules/punk/mix/commandset/layout-999999.0a1.0.tm, src/modules/punk/cap/handlers/templates-999999.0a1.0.tm (ref resolution), src/modules/punk/mix/#modpod-templates-999999.0a1.0/ (module-shipped refs/layouts), src/make.tcl (layout sync steps)
+Goal: project.new generates projects from thin layouts (structure, scripts, docs - no stored bootsupport/module/vfs snapshot trees) whose heavy infrastructure is injected at generation time from the generating shell's own current trees; layout references are fauxlink files (one ref concept repo-wide, no bespoke .ref grammar, no real symlinks); and the documented overlay semantics (custom-over-vendor, .anti deletions, name@base derived layouts, _project staging) are implemented by a single staging-directory materialization primitive - so a bare built kit can generate a current project, and the committed multi-megabyte stale layout snapshots are retired.
+Acceptance: hygiene stage - in a punkshell checkout `dev project.new` with defaulted -layout resolves an exact layout name (no tcl::prefix ambiguity); the no-handler warning paths execute without error (put/puts typos fixed) and an absolute-pathtype provider registration does not raise an expr syntax error; test/junk refs (test2, sample-0.1 duplicate, the a.txt-only punk.shell-0.1) no longer present as selectable layouts; src/project_layouts/README.md describes the implemented punk.templates+refs mechanism including the ref filename grammar. Pivot stage - a project generated from the thin punk.project layout carries bootsupport modules matching the generating shell's current src/bootsupport (verified by comparing a marker module version such as punk::mix::cli, not a stored snapshot vintage); src/project_layouts contains no embedded bootsupport/vfs module trees and make.tcl's layout bootsupport-sync step is retired; layout refs are .fauxlink files resolved via the fauxlink module with the bespoke .ref parser removed, every layout ref carrying a non-empty nominal name (leading-# punkcheck-exclusion hazard documented in this file); a bare built kit run outside any project lists at least the module-shipped punk.project layout and generates a working project from it; and one overlay case exercising custom-over-vendor override, a .anti deletion, and a name@base derived layout (the existing sample-0.1/othersample fixtures) materializes correctly through the staging primitive into a generated project.
+
+## Context
+
+Review of the layout system (2026-07-16) found a coherent three-layer design whose
+centerpiece was never implemented:
+
+1. **punk.templates capability** (punk::mix::templates declarations resolved by
+   punk::cap::handlers::templates) locates template base folders in priority order
+   (module < shellproject < currentproject < absolute < adhoc).
+2. **Layout references** - zero-byte `.ref` files under `decktemplates/*/layout_refs/`
+   whose filename encodes alias + path into `<projectroot>/src/project_layouts`
+   (`alias@vendor+punk+project-0.1.ref`). This indirection is the recursion firewall:
+   modules ship only refs; layout payloads (which embed module trees, including
+   punk::mix::templates itself) live once, outside any module.
+3. **Payload store** `src/project_layouts/{vendor,custom}/{<vendor>,_project}/` with
+   overlay semantics documented in `custom/punk/sample-0.1/extra.txt` (custom over
+   vendor, `.anti` deletion markers, `newname@base` derived layouts, `_project`
+   staging pseudo-vendor).
+
+Unimplemented/broken as found:
+
+- **No merging at all** - project.new copies exactly one resolved directory
+  (punkcheck::install); `.anti`, custom overlays, and `name@base` folders
+  (e.g. `custom/punk/othersample@sample-0.1`) are documented but inert.
+- **module-pathtype refs can never resolve** - their `base` is the module directory,
+  and `get_itemdict_projectlayouts` looks for `<base>/src/project_layouts`, which
+  cannot exist inside a module. Consequence: the only source of the exact name
+  `punk.project` is dead, and a bare kit outside any project has an empty layout list
+  (project.new unusable standalone).
+- **Default -layout is prefix-ambiguous** in-checkout: no exact `punk.project` exists;
+  `tcl::prefix::match` sees `punk.project-0.1` and `punk.project-0.1_overrides`.
+- **Stale fat snapshots**: `vendor/punk/project-0.1` is 559 files / ~19MB frozen at the
+  punk::mix::cli 0.3/0.3.1 era (both versions side by side); `custom/_project/*`
+  duplicates ~23MB more. make.tcl refreshes only the `custom/_project` copies
+  (bootsupport + make/build sync) - treating drift symptomatically.
+- **Names lie**: `@vendor+_project+punk.shell-0.1.ref` presents as `punk.shell-0.1`
+  but targets a folder containing a single junk `a.txt`; the real 12MB shell layout is
+  exposed only as `punk.shell-0.1_overrides`. Test refs (`test2`, `sample-0.1`) show as
+  selectable layouts.
+- **Child materialization missing**: the vendored layout carries a marker folder
+  `src/PROJECT_LAYOUTS_CREATE_FROM_DECKTEMPLATES_LAYOUT_REFERENCES/` (and project.new
+  excludes `src/PROJECT_LAYOUTS_*`); the step it names was never written, so generated
+  projects hold refs pointing at a folder that never exists.
+- **Design-generation residue**: README describes a `punk.projectlayout` capability
+  that exists nowhere in code (punk.templates + refs superseded it); the modpod's
+  `templates/layouts/project` subtree has no reader; make.tcl still carries
+  `old_layout_update_list` referencing `src/mixtemplates`.
+- **Latent bugs**: `put stderr` (missing s) in no-handler warning paths
+  (commandset/layout.tm ~lines 208/219, commandset/project.tm ~line 255); non-braced
+  `if {!file exists $normpath}` in the templates handler's `absolute` branch
+  (~line 175) errors on any absolute-pathtype registration.
+
+The pivot insight: the recursion problem and the snapshot weight have the same cause -
+layouts *store* module trees. Stop storing them (inject at generation time from the
+generating shell, which always has current bootsupport) and: layouts become small
+enough to ship inside the punk::mix::templates module without recursion (a bare kit
+becomes self-sufficient); ~40MB of committed snapshots leaves the repo; overlay merging
+becomes cheap; and generated projects start current instead of at snapshot vintage,
+with later refresh belonging to G-027's pull.
+
+## Approach
+
+Staged; hygiene first since it is independently shippable.
+
+1. **Hygiene** (no design changes): fix the `put`/`!file exists` bugs; restore an exact
+   default layout name (rename `@vendor+punk+project-0.1.ref` to
+   `project@vendor+punk+project-0.1.ref`, yielding exactly `punk.project`); quarantine
+   or ignore-prefix the test/junk refs; rewrite `src/project_layouts/README.md` to
+   describe the implemented system and the ref filename grammar; remove the dead modpod
+   `templates/layouts` subtree and make.tcl `old_layout_update_list` residue.
+2. **Fauxlink refs** (user decision 2026-07-16: one ref concept repo-wide, no real
+   symlinks): migrate `layout_refs/*.ref` to `.fauxlink` files resolved by the vendored
+   `fauxlink` module - `alias@vendor+punk+project-0.1.ref` becomes
+   `alias#vendor+punk+project-0.1.fauxlink` (same `+` path encoding; `@` in target
+   segments like `othersample@sample-0.1` is legal literal fauxlink content). Target
+   paths stay application-resolved against `<projectroot>/src/project_layouts` (fauxlink
+   is app-driven by design). Zero-byte property preserved (target fully in the name).
+   Clean cutover preferred over dual-grammar support - all refs are in-repo.
+   Constraint: layout refs MUST carry a non-empty nominal name - an alias-less ref
+   (`#vendor+...fauxlink`) starts with `#`, which this project's punkcheck core
+   excludes (`#*`, `**/#*`) treat as aside/hidden, so it would silently vanish from
+   punkcheck-driven installs. Opportunities: the fauxlink tags segment can carry layout
+   metadata (e.g. staging markers); the reserved TOML body can carry per-ref update
+   policy (the `allowupdates`/`repo`/`reposubdir` keys currently parked in the
+   punk::mix::templates declarations) - feeding G-027 provenance.
+3. **Thin layouts + injection**: strip stored bootsupport/vfs/module trees from layout
+   payloads; project.new copies the thin layout then injects bootsupport from the
+   generating shell's own current trees (same mechanism make.tcl already uses to sync
+   `custom/_project` layouts, relocated to generation time). Retire make.tcl's
+   layout bootsupport-sync step and the fat `custom/_project` copies. Ship the thin
+   `punk.project` layout (plus its ref) inside the punk::mix::templates module so
+   module-pathtype refs resolve to module-carried payloads and a bare kit works.
+4. **Overlay merge primitive**: a `layout_materialize` lib proc resolving a layout name
+   to an ordered chain of source dirs (base from `name@base` folder naming if present,
+   then vendor/<v>/<name>, then custom/<v>/<name>, then `_project` overlays), composed
+   into a staging directory applying `.anti` deletions; project.new keeps its
+   single-path contract and receives the staged path. Brings every documented-but-dead
+   concept to life at once.
+5. **Retirement/decision**: drop or implement the child-side
+   `PROJECT_LAYOUTS_CREATE_FROM_...` marker (with thin layouts, children need only
+   refs + thin payloads; heavy parts arrive by the same injection and refresh via
+   G-027); decide whether the vendor/custom x `_project` matrix at both levels still
+   earns its complexity once overlays are cheap (vendor/_project and custom/_project
+   may collapse into one override level).
+
+## Alternatives considered
+
+- Real filesystem symlinks for refs - rejected: platform-finicky (Windows privilege
+  and VCS behaviour), and fauxlink exists precisely to avoid them (user preference,
+  2026-07-16).
+- Keeping the bespoke `.ref` grammar - rejected: it is a hand-rolled subset of
+  fauxlink's naming scheme; two ref concepts in one repo with near-identical encodings
+  invites drift.
+- Teaching punkcheck::install multi-source layered installs - rejected in favour of
+  staging-directory composition: simpler, independently testable, preserves
+  project.new's single-path contract.
+- Keeping fat vendor snapshots and fixing drift via pull updates alone - rejected as
+  end state: the snapshots would still be redundant third/fourth copies of bootsupport
+  content, still 40MB in-repo, and the recursion constraint on module-shipped layouts
+  would remain.
+
+## Notes
+
+- fauxlink upstream source is directly accessible at C:/repo/jn/tclmodules/fauxlink
+  (fossil checkout, punkshell-style layout; user confirmed 2026-07-17): fauxlink tests
+  or module changes needed for the stage-2 ref migration can be made upstream there and
+  re-vendored, rather than patching the vendored copy.
+- Related goals: G-086 (light project layout - becomes just another thin layout with
+  less injected; this goal generalizes its premise to all layouts), G-027
+  (derived-project pull updates - takes over post-generation refresh; fauxlink TOML
+  body is a candidate carrier for its provenance/update-policy records), G-012
+  (template payload safety - inert VCS-config payload rules apply to thin layouts
+  unchanged), G-004 (no committed binaries - snapshot retirement aligns), G-026
+  (vendor provenance policy - source-side cleanliness for injection).
+- Naming rules to enforce with the merge primitive: visible name = vendor.name derived
+  from the ref; report colliding visible names in `dev project.layouts`; versionless
+  request picks highest version (existing todo in commandset/project.tm); default
+  -layout must be an exact name.
+- The `#n` duplicate-suffix mechanism in `_get_itemdict` and the priority ordering
+  (module < shellproject < currentproject < absolute < adhoc) are sound and carry over
+  unchanged.
+
+## Progress
+
+### 2026-07-17 hygiene stage complete (increment 1)
+
+Landed (punk::mix::commandset::layout 0.1.1, project 0.2.2, module 0.1.1,
+scriptwrap 0.1.1; punk::mix::base 0.1.1; punk::cap::handlers::templates 0.1.1;
+punk::mix::templates 0.1.4; punkshell 0.12.38):
+
+- put -> puts fixed at all six no-handler warning sites. The closeout sweep found
+  three sites beyond the review's list (mix/base get_template_basefolders,
+  commandset::module templates_dict, commandset::scriptwrap templates_dict). Three
+  procs also dereferenced an unset result variable after the warning - the
+  no-handler paths now warn and return an empty dict; layout/module warning
+  messages no longer misattribute their owning proc.
+- templates handler: the non-braced 'if {!file exists $normpath}' expr bug fixed.
+  Verification exposed an adjacent latent bug, also fixed: pkg_register's
+  duplicate-registration guard did 'dict get $provider_info $pkg' without a
+  dict-exists check, erroring for any second provider package registering the
+  same capability.
+- @vendor+punk+project-0.1.ref renamed to project@vendor+punk+project-0.1.ref:
+  exact layout name 'punk.project' now exists and the defaulted -layout
+  prefix-resolves unambiguously.
+- Junk refs deleted: test2, the custom/_project duplicate sample-0.1 ref, and the
+  alias-less punk.shell-0.1 ref together with its a.txt-only target folder
+  (project_layouts/vendor/_project/punk.shell-0.1).
+- src/project_layouts/README.md rewritten: implemented punk.templates + layout_refs
+  mechanism, ref filename grammar, unimplemented-overlay status, G-087 pointer;
+  dead punk.projectlayout capability description removed.
+- Dead modpod templates/layouts/project payload removed (punk::mix::templates
+  0.1.4); make.tcl old_layout_update_list and stale mixtemplates help text removed.
+
+Verification (2026-07-17, native tclsh 8.7/9 runtests + rebuilt root modules):
+
+- Scratch script (g087_hygiene_verify.tcl) 13/13: exact punk.project present and
+  tcl::prefix::match resolves it; test2 / bare sample-0.1 / punk.shell-0.1 absent
+  from layouts_dict; absolute-pathtype registration returns 1 for an existing path
+  and warn+0 for a missing one; with the handler entry blanked, all five
+  no-handler paths warn and return empty without error.
+- runtests: prune 19/19, fossilmove 10/10, multishell 9 pass + 1 skip,
+  libsearch 8/8. make.tcl modules builds clean; rebuilt templates modpod 0.1.4
+  mounts and its module-shipped ref lists as punk.project#2 (module-pathtype
+  resolution still dead pending stage 3).
+- Resulting layout names: punk.sample-0.1 punk.project punk.minimal punk.basic
+  punk.shell-0.1_overrides punk.project-0.1_overrides.
+
+Remaining for acceptance (pivot stage - Approach stages 2-5):
+
+- fauxlink ref migration (stage 2).
+- thin layouts + generation-time bootsupport injection, retire make.tcl layout
+  bootsupport-sync, module-shipped thin punk.project layout for bare kits (stage 3).
+- staging-directory overlay merge primitive exercising the sample-0.1/othersample
+  fixtures (stage 4).
+- child-side PROJECT_LAYOUTS_CREATE_FROM_... marker retirement and the
+  vendor/custom x _project matrix decision (stage 5).