✨ feat: register a URI handler, so anything can open a log in the viewer

[lukecotter]

✨ Feature Request

Register a URI handler, so anything outside VS Code can open a log in the viewer.

🧩 Problem This Solves

Nothing outside VS Code can ask the extension to open a log.

lana.showLogAnalysis already takes a vscode.Uri
(lana/src/commands/ShowLogAnalysis.ts:15-17), and activation covers both
onLanguage:apexlog and onStartupFinished, so the capability is there. But
package.json declares no uriHandler and extension.ts calls no
vscode.window.registerUriHandler, so there is no vscode://financialforce.lana/...
entry point.

Only code already running inside the extension host can call executeCommand. A
separate process cannot.

🧠 Proposed Solution

Register a URI handler that maps to the two existing commands:

vscode://FinancialForce.lana/showLogAnalysis?path=<absolute log path>
vscode://FinancialForce.lana/showInLogAnalysis?timestamp=<ns>&path=<absolute log path>

The second matches the undeclared lana.showInLogAnalysis, which already takes
{ timestamp, filePath? }.

Notes for whoever picks this up:

• Insiders uses the vscode-insiders:// scheme. vscode.env.uriScheme gives the running
  one, but a caller building the link from outside has to choose, so document both.
• Validate path: it arrives from outside the editor. Refuse anything that is not an
  existing readable file.
• Decide the behaviour when the path is not in any open workspace folder.

Acceptance

• open "vscode://FinancialForce.lana/showLogAnalysis?path=/abs/path/to.log" opens the
  log in the analysis view from a cold editor.
• A path that does not exist reports an error and opens nothing.

🔄 Alternatives

A fifth MCP tool, considered and rejected. The MCP server can run remotely, in a
container, or over SSH, where no VS Code is reachable, and the dependency runs the wrong
way — the extension registers the server, not the reverse. A URI is the right shape:
anything that can open a link can use it, and a caller that cannot reach a desktop simply
does not build one.

📎 Additional context

The Apex Log MCP server (certinia/debug-log-analyzer-mcp) is one caller. Every one of
its tools returns an absolute log file path, and apexlog_execute_anonymous writes a
new log to disk. An agent that has just found a slow operation has no way to say "show
me this in the viewer".