Build M0 Garden to Gate route skeleton

[JOY]

Parent

• Part of Track alpha demo implementation umbrella #260.

Source Docs

• docs/design/128-alpha-route-camera-readability-and-screenshot-gates.md
• docs/design/127-alpha-location-naming-and-map-label-contract.md
• docs/design/116-alpha-m0-route-skeleton-builder-brief.md
• docs/design/112-alpha-map-implementation-slice-order-and-cut-plan.md
• docs/design/114-alpha-map-playtest-evidence-manifest.md
• docs/design/148-open-design-decision-backlog.md
• docs/design/115-alpha-map-implementation-issue-split-and-agent-packets.md
• docs/design/90-alpha-scene-blockout-object-list-and-shot-plan.md
• docs/design/104-alpha-garden-to-ash-underpass-route-node-graph.md
• docs/design/89-alpha-control-camera-and-combat-input-baseline.md
• docs/playtests/README.md

Evidence Index And Template

• docs/playtests/README.md
• docs/playtests/_templates/alpha-map-slice-M0/

Goal

Build the M0 alpha map scene skeleton so a player can move from Clinic spawn to Garden Court, Body Hall pad, Mission Board / Gate Registry pad, and the Ash Underpass route marker without relying on final art or optional content.

Allowed Scope

• Player start.
• Garden Main Court rough route.
• Body Hall pad placeholder.
• Mission Board / Gate Registry pad placeholder.
• Ash Underpass route marker.
• Camera check markers.
• Temporary labels needed for route proof.

Forbidden Scope

• Boss arena.
• Final props.
• Full facility UI.
• Full mission logic.
• NPC patrol polish.
• Material or lighting polish.

Acceptance

• Capture M0_01_Garden_Orientation.png.
• Capture M0_02_BodyHall_Pad.png.
• Capture M0_03_MissionBoard_Pad.png.
• Add route note proving Clinic to Mission Board to Ash Underpass route marker.
• Add Unity console summary if Unity was touched.
• Add promotion-gate-note.md saying whether M1 can start, is blocked, or can start with mock-only caveats.
• Evidence folder follows docs/design/114-alpha-map-playtest-evidence-manifest.md, docs/design/116-alpha-m0-route-skeleton-builder-brief.md, docs/playtests/README.md, and the M0 evidence template.
• Route labels and player-facing map copy follow the current Dayton and TIME-class geography decisions, or clearly mark unresolved wording as blocked.
• No Unity scene mutation happens outside the integration workspace or a locked validation owner.

Notes

This is the first practical split from the #260 umbrella. Do not start M1/M2/M5 polish from this issue unless M0 evidence is already captured.

[JOY]

Design handoff is now in the repo. No code or Unity scene changes are required for this issue before implementation.

Primary builder brief:

• docs/design/116-alpha-m0-route-skeleton-builder-brief.md

Evidence template:

• docs/playtests/_templates/alpha-map-slice-M0/

Source docs to keep open while building:

• docs/design/112-alpha-map-narrative-and-identity-pass.md
• docs/design/114-alpha-map-playtest-evidence-manifest.md
• docs/design/115-alpha-map-implementation-issue-split-and-agent-packets.md
• docs/design/90-alpha-zone-mission-layout.md
• docs/design/104-alpha-garden-to-gate-route-design.md
• docs/design/89-alpha-dungeon-space-blockout.md

Implementation focus:

• Make the Garden -> Gate route walkable.
• Preserve orientation landmarks and a clear player path.
• Capture M0 route screenshots and route notes in the template.
• Keep combat, roster UI, backend authority, and final polish out of this slice unless they are already available as integration evidence.

[JOY]

Docs-only M0 source recovery is now in the worktree.

Added the source docs and evidence template referenced by this issue:

• docs/design/116-alpha-m0-route-skeleton-builder-brief.md
• docs/design/112-alpha-map-implementation-slice-order-and-cut-plan.md
• docs/design/114-alpha-map-playtest-evidence-manifest.md
• docs/design/115-alpha-map-implementation-issue-split-and-agent-packets.md
• docs/design/90-alpha-scene-blockout-object-list-and-shot-plan.md
• docs/design/104-alpha-garden-to-ash-underpass-route-node-graph.md
• docs/design/89-alpha-control-camera-and-combat-input-baseline.md
• docs/playtests/README.md
• docs/playtests/_templates/alpha-map-slice-M0/

Also linked the M0 lane into:

• docs/SUMMARY.md
• docs/design/03-systems-index.md
• docs/setup/github-project-tracking.md
• ROADMAP.md

Verification:

• tools/windows/check-backlog-sync.ps1 OK
• git diff --check OK
• no generated em-dash/en-dash matches in touched files
• local markdown links OK
• SUMMARY coverage OK for current design docs
• all Build M0 Garden to Gate route skeleton #280 source docs and the M0 template entry exist

No Unity scene or code changes were made. This does not complete #280 implementation; it makes #280 buildable by giving the Unity owner the missing brief, node graph, shot plan, and evidence template.

[JOY]

Implemented and merged via PR #292.

Evidence:

• Merge commit: 7205f88
• Scene route root: Unity/Assets/_SecondSpawn/Scenes/ZoneTest_Hub.unity with _AlphaM0RouteSkeleton
• Builder menu: Second Spawn/Alpha/Build M0 Route Skeleton And Evidence
• Evidence folder: docs/playtests/alpha-map-slice-M0/2026-05-29-m0-route-skeleton/
• PNG evidence: Garden orientation, Body Hall pad, Mission Board pad, Ash Underpass route marker
• Promotion verdict: M1 can start with mock-only caveats

Verification:

• GitHub markdown-lint passed on PR Build alpha M0 Garden to Gate route skeleton #292.
• Local review fallback approved with the known Unity worktree batchmode caveat.
• Root and unity-validation are clean; preflight passed with only unity-validation registered.