fix: auto-sanitize hyphenated dolt_database on embedded-mode upgrade (post-#2142 gap)

[kevglynn]

Summary

Projects initialized before #2142 (or via --database with hyphens) retain hyphenated dolt_database names in metadata.json. When upgrading to bd 1.0.0 — which defaults to embedded mode — embedded Dolt rejects these names with an unhelpful invalid database name error. All beads become inaccessible until the user manually edits metadata.json.

This is a remaining gap from the #2142 fix, which only addressed new bd init runs.

Problem

How it happens

1. User has project my-project initialized before bd init should sanitize hyphens to underscores in dolt_database name #2142, or used --database my-project (which passes ValidateDatabaseName since it allows hyphens)
2. metadata.json contains "dolt_database": "my-project"
3. User upgrades to bd 1.0.0 (embedded mode default)
4. Every bd command fails: invalid database name: "my-project"

Gaps in current code

Component	Issue
newDoltStoreFromConfig	Passes hyphenated name directly to embedded engine — no sanitization
embeddeddolt error	Says invalid database name with no guidance on how to fix it
bd doctor	Hyphen check only runs in server mode (RunServerHealthChecks); embedded-default projects skip it entirely
ValidateDatabaseName	Allows hyphens ([a-zA-Z0-9_\-]), but embedded mode rejects them — inconsistent
checkMetadataConfigValues	Does not check dolt_database for embedded-incompatible characters

Impact

Any pre-#2142 project in a hyphenated directory (very common: my-project, cool-app, jtbot-core) becomes completely unusable after upgrading to embedded mode. The workaround — manually adding "dolt_mode": "server" or editing dolt_database — is undiscoverable.

Proposed Fix

1. Auto-sanitize on embedded store open (store_factory.go)

When newDoltStoreFromConfig is about to open an embedded store with a hyphenated database name:

• Sanitize hyphens → underscores
• Rename the existing database if it exists with the old name
• Persist the sanitized name back to metadata.json
• Log the migration for visibility

2. Better error in embedded mode (embeddeddolt/open.go, store.go)

If identifier validation fails and the name contains hyphens, add actionable guidance:

invalid database name "my-project": hyphens are not allowed in embedded mode.
Run 'bd doctor --fix' or replace hyphens with underscores in .beads/metadata.json dolt_database field.

3. Doctor check for embedded mode (doctor/config_values.go)

Add a dolt_database validation to checkMetadataConfigValues that flags hyphenated names when dolt_mode is not server.

4. Align --database validation with embedded mode (init.go)

When --database is provided and the build will use embedded mode, reject names that contain hyphens early (before any side effects).

Environment

• bd HEAD (0ed8d0b)
• Affects any pre-bd init should sanitize hyphens to underscores in dolt_database name #2142 project upgrading to embedded-mode-default builds

Related

• bd init should sanitize hyphens to underscores in dolt_database name #2142 (original sanitization fix for new projects)
• bug: pre-#2142 dolt migrations missing dolt_database in metadata.json #2160 (missing dolt_database in metadata.json for pre-bd init should sanitize hyphens to underscores in dolt_database name #2142 migrations)
• fix(init): bd init silently corrupts metadata when directory name contains dots (e.g. Julia packages) #3128 (dot sanitization follow-up)