Shape blob storage: sync FreeCAD custom tool shapes (.fcstd) as content-addressed blobs

[sliptonic]

Why

In loobric-freecad's asset-store mode, tool libraries are served from the server. A toolbit referencing a custom shape (.fcstd) renders wrong or fails to instantiate on any seat that lacks the shape file locally — shape references sync today, shape contents do not. This is the one designed follow-up that store-mode v1 ships around (v1 warns on pull when a referenced shape is missing locally).

What

Server-side storage for shape blobs with:

• Content-hash identity — a shape is identified by a digest of its bytes, so the same shape referenced by 40 tools is stored once and renaming a file doesn't fork it
• Association with ToolInstanceRecords via the existing reference (the .fctb's shape name stays the client-facing handle; the record carries the hash)
• Versioning — a re-uploaded shape with new content is a new blob; records point at a specific hash
• Size limits and media-type validation (these are opaque binary .fcstd documents; the server never parses them)

The existing media-attachment mechanism (attach_media_from_url, MCP 1.2.0) may be the foundation or a sibling — needs a deliberate decision rather than reuse-by-default, since media is per-record and shapes are shared across records.

Explicitly out of scope

• Built-in FreeCAD shapes (every seat has them; only custom shapes sync)
• Parsing/validating shape geometry server-side
• .fcm machine configs — permanent non-goal; post/kinematics config is not Loobric's domain

Client behavior this unblocks

FreeCAD addon serves toolbitshape assets from the mirror like toolbits: a pulled tool arrives with its custom shape, multi-seat just works.

🤖 Generated with Claude Code